DISEASE CONTROL IN AQUACULTURE IS, AND WILLaquaexpoguayaquil.cna-ecuador.com/wp-content/uploads/2017/10/P… · FUTURE MICROBIAL MANAGEMENT STRATEGIES TO CONTROL EMS TREATMENTS UNDER

210/5/2017

DISEASE CONTROL IN AQUACULTURE IS, AND WILL REMAIN, A FOCUS POINT

1960-1970 19901980 2000

Start

industrial

farming

2010 2020

Optimizing reproduction

protocols, nutrition and culture

systems

2017

310/5/2017

Walker and Mohan (2009)

20161970 19901980 2000

Start

commercial

farmingIHHNV

MBV

YHV

TSV

WSSV

GAVMSGS

IMNV EMS

EHP

vibriosis

DISEASES, A PROBLEM OF INCREASING INDUSTRIALISATION

Start

industrial

farming

410/5/2017

1960-1970 19901980 2000 2010 20202017

Optimizing reproduction

protocols, nutrition and culture

systems

Developing and optimizing disease

control strategies

Developing and optimizing disease

control strategies

DISEASES, A PROBLEM OF INCREASING INDUSTRIALISATION

510/5/2017

Walker and Mohan (2009)

20161970 19901980 2000

Start

commercial

farmingIHHNV

MBV

YHV

TSV

WSSV

GAVMSGS

IMNV

EHP

vibriosis

EARLY MORTALITY SYNDROME IN SHRIMP FARMING

EMS

610/5/2017

- Shrimp post-larvae

- 10 - 30 days after stocking in grow-out pond

- causes up to 100 % mortality

- 5-7 $ bn losses in Thailand (2011-2015); > 10 $ mln losses in

Mekong Delta in 2015

China (2009)

Vietnam (2010)

Malaysia (2011)

Thailand(2012)

Mexico (2013)



- Caused by Vibrio parahaemolyticus

- Contains plasmid with pirA and pirB toxin encoding genes

Xiao et al. (2017)

810/5/2017

INITIAL APPROACH OF MICROBIAL MANAGEMENT: USE OF ANTIBIOTICS TO CONTROL EMS

Only focus was on killing the bad bugs

PATHOGENHOST DISEASE

CULTURE SYSTEM

PATHOGEN + all other bacteria

“ANTIBIOTICS USE INTENDED TO REDUCE LOSSES DUE TO THE EARLY MORTALITY SYNDROME (EMS/AHPNS) IN SHRIMP FARMS IN VIET NAM” By Loc H. Tran et al. (2013)

Bacterial isolates in Vietnam were investigated for antibiotic resistance against oxytetracycline

97/9/2017

PRESENTATION WORLD AQUACULTURE SOCIETY -WAS 2013

EMS-causing V. parahaemolyticus

Non EMS-causing V. parahaemolyticus

2011/2012 0% resistant 0% resistant

EMS-causing V. parahaemolyticus

Non EMS-causing V. parahaemolyticus

2011/2012 0% resistant 0% resistant

2013 85,7% resistant 100% resistant

1010/5/2017

ANTIBIOTIC USE IN MEXICO TO CONTROL EMS

1110/5/2017

The evolution of bacteria on a “mega-plate” petri dish – Kishony Lab;

Harvard Medical School

WHAT HAPPENS WHEN WE USE ANTIBIOTICS?

1210/5/2017

BALANCED HEALTH TO MINIMIZE EMS RISK

RESILIENCE CHALLENGE

ON FARM

DISEASE

CHALLENGE

NUTRITION

IMMUNITY

GENETIC

RESISTANCE

- MINIMIZE “RED STACK” AND MAXIMIZE “GREEN STACK”

Vision

New approach of microbial management = control the presence and/or activity of bad bugs AND good bugs

137/9/2017

PATHOGEN

CULTURE SYSTEM

- Avoid entrance

and transmission

of the plasmid

CURRENT MICROBIAL MANAGEMENT STRATEGIES TO CONTROL EMS

1410/5/2017


AVOIDING ENTRANCE INTO THE SYSTEM

- BIOSECURITY

Vision

1410/5/2017

Specific pathogen

free (SPF)

Disinfection protocol in Thailand

157/9/2017


HOST

CULTURE SYSTEM

- Steer gut colonizationPATHOGEN - Use of bacteria

- Avoid entrance

and transmission

of the plasmid

1610/5/2017


USE OF GOOD BACTERIA TO CONTROL BAD BACTERIA -PROBIOTICS

1710/5/2017


PROBIOTICS

Mayo/Junio 2017 Vol. 22

1810/5/2017


PROBIOTICS

Disease challenge test in collaboration with Can Tho University (Vietnam)

1910/5/2017


PROBIOTICS

Munoz et al. 2014. Global Aquaculture Advocate. Sept-

Oct 2014, 50-52

207/9/2017


HOST

CULTURE SYSTEM


- Avoid entrance

and transmission

of the plasmid

- Use of plant

components

2110/5/2017

FUTURE MICROBIAL MANAGEMENT STRATEGIES TO CONTROL EMS

TREATMENTS UNDER INVESTIGATION: USE OF PLANT COMPONENTS

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9

1 4 7 1013161922252831343740434649

OD

60

0n

m

Time (h)

Growth Streptococcus agalactiae in presence of plant compound 1

0

25

50

100

250

500

0

0,1

0,2

0,3

0,4

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0,6

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1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49

Time (h)

Growth of Aeromonas salmonicida in presence of plant compound 3

0

25

50

100

250

500



Product applied in the culture water during 24h PL10 transport.

➢ Drastic reduction of Vibrio in transport water and shrimp.

1,E+00

1,E+01

1,E+02

1,E+03

1,E+04

1,E+05

1,E+06

Postlarvae Water Postlarvae Water

Vibrio sp. Vibrio parahaemolyticus

CFU

/ml o

r p

ost

larv

ae Control

Plant compound

based product

2310/5/2017




247/9/2017


HOST

CULTURE SYSTEM


- Avoid entrance

and transmission

of the plasmid

- Use of plant

components

- Increase nutrition and

immunity

2510/5/2017


TREATMENTS UNDER INVESTIGATION: BOOSTER DIETS

• Optimal nutrition for postlarval shrimp• Contains immunostimulants• Neutralisation of EMS bacteria

• Partial replacement of nursery or grow-out diet during critical period

Improve overall resilience of the shrimp

2610/5/2017



15% Booster diet

15% Booster diet

2710/5/2017




287/9/2017


HOST

CULTURE SYSTEM


- Avoid entrance

and transmission

of the plasmid

- Use of plant

components

ENVIRONMENT - Modify system

operational

parameters

- Increase nutrition and

immunity

2910/5/2017

NEW MICROBIAL MANAGEMENT STRATEGIES TO CONTROL EMS

MODIFICATION OF SYSTEM OPERATIONAL PARAMETERS

Based on knowledge on ecology of the pathogen…

Vibrio parahaemolyticus = Vibrio sp.Vibrio sp. = normal component of marine environments

opportunistic pathogens

… it is possible to modify the system and set-up selection regime to outcompete vibrios

neutral/beneficial bacteria

harmful bacteria (obligate pathogens)

potentially harmful bacteria

(opportunists)

What do we want???

- all bacteria are eliminated

In order to eliminate bad bacteria: disinfection

- but, new bacterial colonization starts: difference r-strategists ( ) and K-strategists ( )!!!!

ecological characteristics of

Importance for shrimp

Dangerous; opportunistic pathogens;

EMS causing bacteria

Generally harmless

Growth rate upon enrichment

HIGH LOW

Dominance? Unstable environmental conditions

Stable environmental conditions

K-strategist bacteriar-strategist bacteria

Initially: Low number of bacteria and a lot of nutrients

Stimulates r-strategist bacteria

Substrate per bacterium = HIGH; niches are openTime

What happens at the microbial level after

disinfection?

In the mean time:

K-strategist bacteria grow slowly

TimeSubstrate per bacterium = HIGH; niches are open

What happens at the microbial level after

disinfection?

SYSTEM DESIGN IN TIMES OF EMS

(Taw, 2017)

Prior to EMS

Time

What happens in the long run?

substrate/bacterium remains HIGH

Standard systems: a lot of nutrients and wash-out

r-strategist bacteria dominate

Timesubstrate/bacterium remains HIGH

Standard systems: a lot of nutrients and wash-out

r-strategist bacteria dominate


Timesubstrate/bacterium remains HIGH


introduction of animals: typically during massive microbial growth

4010/5/2017

- Industrial approach to control EMS in Asia

Minimize waste within the system (remove nutrients)Shrimp toilets

Minimize exchange of water with the external environmentRecirculation of the water

SYSTEM MANAGEMENT TO MINIMIZE DISEASE RISK

- Industrial approach to control EMS (Asia)

(Taw, 2017)

After EMS

SYSTEM MANAGEMENT TO MINIMIZE DISEASE RISK

Prior to EMS

Transition: High number of bacteria and less nutrients

Collapse of r-strategist bacteria

TimeSubstrate per bacterium = LOW; niches are taken

What happens at the microbial level because of RAS and

removal of excess waste?

Transition: High number of bacteria and less nutrients

K-strategist bacteria continue to grow

TimeSubstrate per bacterium = LOW; niches are taken

What happens at the microbial level because of RAS and

removal of excess waste?

r selection

K selection

Time

Consequence of alternative system operations implied by

shrimp farmers

Animals live in environment controlled for V. parahaemolyticus dominance, but also opportunists (e.g. Vibrio) in general

r selection

K selection

Time

Consequence of alternative system operations implied by

shrimp farmers

introduction of animals: typically during massive microbial growth

r selection

K selection

Time

Similar RAS methodology will also work for control of

vibrios in general, both in farm and in hatcheries

477/9/2017

HORIZONTAL TRANSFER OF EMS PLASMID AMONG BACTERIA

HORIZONTAL TRANSFER OF EMS PLASMID AMONG BACTERIA

487/9/2017

Problem of horizontal transfer implies the need to control not

only EMS-causing V. parahaemolyticus,

but Vibrio in general!!

SUMMARY

- BIOSECURITY IS KEY; AVOID ENTRANCE

- PROBIOTICS, BOOSTER DIETS AND PHYTOBIOTICS CAN CONTRIBUTE IN CONTROLLING EMS, HOWEVER ARE NOT THE ONLY SOLUTION!

- SYSTEM OPERATIONS SHOULD BE (RE)CONSIDERED TO MINIMIZE DISEASE RISK. KEY IS TO ENSURE MICROBIAL STABILITY

- COMBINATION OF THE ABOVE WILL MAXIMIZE THE SUCCESS OF SHRIMP CULTURE IN TIMES OF EMS

4910/5/2017

5010/5/2017

Documents

DISEASE CONTROL IN AQUACULTURE IS, AND WILLaquaexpoguayaquil.cna-ecuador.com/wp-content/uploads/2017/10/P… · FUTURE MICROBIAL MANAGEMENT STRATEGIES TO CONTROL EMS TREATMENTS UNDER