Review of alternatives to antimicrobials pertaining to diseases affecting shrimps

Transcription

1 FMM/RAS/298: Strengthening capacities, policies and national action plans on prudent and responsible use of antimicrobials in fisheries Workshop 2 in cooperation with Malaysia Department of Fisheries and INFOFISH 7-9 August 2017, Kuala Lumpur, Malaysia Review of alternatives to antimicrobials pertaining to diseases affecting shrimps Celia R. Lavilla-Pitogo celia.pitogo@fulbrightmail.org

2 From the presentation of Dr Indrani Karunasagar in Mangalore

3 From the presentation of Dr Indrani Karunasagar in Mangalore

4 Alternative approaches to reduce diseases in shrimp farming (Kaustky et al. 2000) Ecological solution Technological solution 1. Lower intensity and pond densities 1. Isolate farm from the environment 2. Create large buffer zones 2. Treat and re-circulate pond water 3. Integrate systems for effluent treatment and resource management 4. Keep farming within carrying capacity of local environment 3. Sterilize pond environment 4. Use of antibiotics and medicines 5. Genetic selection for disease resistance

5 More lessons to learn! Ecological solution Technological solution Industry approaches Comment 1. Lower intensity and pond densities 1. Isolate farm from the environment Biosecurity geared towards exclusion of viruses Should we bring culture indoors? Biosecurity was not AHPNDproof Now there s EHP Grace Chang s presentation in AHPND Bangkok 2. Create large buffer zones 2. Treat and re-circulate pond water - YES Not fully accepted because of cost of land and/or set up Brazil example br/aquascience/asen/index.html 3. Integrate systems for effluent treatment and resource management 3. Sterilize pond environment Yes as part of biosecurity; failed; allowed AHPND Microbially mature water an idea of the 90s? 4. Keep farming within carrying capacity of local environment 4. Use of antibiotics and medicines YES then NO Supra intensive systems very high input Sulawesi?? 5. Genetic selection for disease resistance YES See next slides

6 Camanor example (Brazil)

7

8 Alday-Sanz, 2016 (AHPND Bangkok Workshop)

9 Alday-Sanz, 2016 (AHPND Bangkok Workshop)

10 Alday-Sanz, 2016 (AHPND Bangkok Workshop)

11 Alday-Sanz, 2016 (AHPND Bangkok Workshop)

12 Vibriosis in Vibriosis shrimp is grow-out shrimp culture The shrimp pond is like a bank! A lot is deposited; very little is withdrawn. Thousands of postlarvae with + vibrios associated bacteria S h r i m p Feces, metabolites, old exoskeleton, mortalities + vibrios Feeds Vitamins, additives, binders, uneaten pellets + vibrios Rearing pond Algae and zooplankton grow and die Organic matter builds-up Water quality changes Microorganisms grow Biofilms form Fertilizers Probiotics, lime and other chemicals + vibrios + vibrios? Urea

13 Vibriosis is shrimp

14 Schematic overview of different strategies to prevent and control luminescent vibriosis without using antibiotics (Defoirdt et al., 2007) Improvement of health; good feed quality Stress prevention: avoid handling, changes in water quality and overstocking Stimulation of the defense system: immunostimulation, vaccination Good hygiene: quarantine, disinfection Water quality optimization: bioaugmentation, water treatment Killing: phage therapy Growth inhibition: Short chain fatty acids Virulence inhibition: quorum sensing disruption Antagonism: probiotics application

15 Summary of alternative biocontrol measures directed toward luminescent vibriosis Phage Therapy Positive aspects: Specific killing of pathogens No effect on harmless and beneficial bacteria Negative aspects: Resistance development by alteration of phage attachment sites Too narrow host range Possible transfer of virulence factors Possible solutions: Careful screening Use of phage cocktails or phage components instead of intact phage

16 Summary of alternative biocontrol measures directed toward luminescent vibriosis Short chain fatty acids and poly-b-hydroxybutyrate Positive aspects: Effective in Artemia model system Use of PHB is economically attractive Negative aspects: Effectiveness needs to be confirmed in other host system Possible solutions: Careful screening Use of phage cocktails or phage components instead of intact phage Quorum sensing disruption Positive aspects: No selective pressure, low risk of resistance development Negative aspects: Technology for practical application not yet available?

17 Summary of alternative biocontrol measures directed toward luminescent vibriosis Probiotics Positive aspect: Take advantage of natural antagonism; different modes of action possible Negative aspect: High doses needed; in many cases not able to maintain themselves Possible solution: Selection procedure; different modes of action; isolation from systems in which they will be applied Green water (good for small scale aquaculture) Positive aspect: Control measure is part of the system (integrated aquaculture) Negative aspect: Effectiveness in controlling disease still has to be proven?

18 The greenwater technique based on SEAFDEC-ASEAN Manual on Best Practices Pond lay-out of a low-discharge/recirculating shrimp farm at SEAFDEC, Philippines. Blue arrows indicate water flow in a low-discharge system; red arrows indicate water Flow in a closed-recirculation system.

19 Grace Chang s presentation at AHPND Workshop, Bangkok June 2016

20 SEND CORRECT MESSAGES

21 Thank you for your attention J