The document discusses the use of bacteriophages (phages) as a treatment for bacterial infections in aquaculture. Phages are viruses that infect and replicate within bacteria. They have a lytic life cycle where they destroy the bacterial host. Phages are highly specific, only infecting certain bacterial strains, and do not harm normal microbiota. The document outlines strategies for developing phage therapies, including isolation, characterization, and testing of phages. It discusses methods of application in aquaculture like oral administration and immersion. Several examples of successful uses of phages to treat bacterial diseases in aquaculture species are provided. Advantages like specificity and ease of propagation are discussed, as well as limitations such as bacterial

1. Phagebiotics: A New Horizon for
Therapeutics in Aquaculture
Phagebiotics: A New Horizon for
Therapeutics in Aquaculture
Presented by
MD. IDRISH RAJA KHAN
Registration no: CAU/55-F/15(M)
DEPARTMENT OF AQUATIC HEALTH AND ENVIRONMENT
COLLEGE OF FISHERIES, CAU, LEMBUCHERRA, TRIPURA

2. BacteriophageBacteriophage
Bacteriophages are
the viruses of bacteria.
Bacteriophages - highly
specific to host bacteria
Since they are specific can
only destroy the harmful
bacteria without affecting
the regular microflora.
Bacteriophages are
the viruses of bacteria.
Bacteriophages - highly
specific to host bacteria
Since they are specific can
only destroy the harmful
bacteria without affecting
the regular microflora.
Fig. 2 – Life cycle of bacteriophage
Two stage life cycle-
1.Lytic
2.Lysogenic
Two stage life cycle-
1.Lytic
2.Lysogenic

3. Strategies for Bacteriophage Therapy in
Aquaculture
• Isolation of bacteriophages
• Characterization and typing
• Assessment of therapeutic efficacy
• Field trial at different agro-climatic condition

4. Lysis assay
Plaque assay
TEM image

5. Mode of application of phages in
aquaculture
• Oral administration through feed
• Immersion
• Intramuscular or intraperitoneal administration
• Direct release of phages in culture system
• Anal intubation

6. Use of bacteriophage in AquacultureUse of bacteriophage in Aquaculture
N
o.
Bacteriophage Mode of application References
1 Vibrio alginolyticus (pVa-21) Dispersed in water Kim et al . (2019)
2 Edwardsiella anguillarum Spontaneously Paentelis et al .
(2019)
3 Flavobacterium psychrophilum (Rainbow trout ) Oral administration Valentina L. Donati
et al. (2018)
4 Aeromonas salmonicida phage AS-A
(Senegalese sole- Solea senegalensis)
Oral administration
Intraperitoneal injection
Silva et al. (2016)
5 V. parahaemolyticus phage (VP1, VP7 and VP9)
(Penaeus monodon)
Dispersed in water
 Oral administration
Alagappan et al.
(2016)
6 A. hydrophila phages pAh1-C and pAh6-C
(cyprinid loach- Misgurnus anguillicaudatus)
Oral administration
Intraperitoneal injection
Jun et al. (2013)
7 Flavobacterium columnare phages (FCP1 and
FCP9) (Clarias batrachus)
Oral administration
Intraperitoneal injection
Immersion
Prasad et al. (2011)
8 V. harveyi phage (Penaeus monodon) Dispersed in water
 Oral administration
Karunasagar et al.
(2007)

7. Advantages of Phage Therapy
• Phages are considered as omnipresent
• Usually specific to a single species or even strains
of pathogenic bacteria
• Easy to isolate and propagate as they are self
replicating
• Resistantance to environmental condition

8. Limitations of phage application
• Requires the exact identification of bacterial
species that cause infection.
• Optimum doses and mode of administration
• Bacterial resistance to phages
• Proper regulatory approvals

9. Phage Cocktail
• Two or more phages together
• Combination of phage with other therapeutics
like antibiotics, lysozyme etc

10. Phage Display Vaccine
• Phage-displayed vaccines are the phages with
peptide or protein antigens genetically displayed
on their surfaces as well as those with antigens
chemically conjugated or biologically bound on
their surfaces.

11. Platform Phage
• Free of toxin and virulent genes
• Engineered for better host range

13. ReferencesReferences
• Ackermann, H.W. (2012.) Bacteriophage electron microscopy. Adv Virus Res., 82: 1-32. doi:
10.1016/B978-0-12-394621-8.00017-0.
• Adams, M.H. (1959) Bacteriophages. New York, NY, USA: Interscience.
• APHA (2005).Standard Methods for the Examination of Water and Wastewater (21st ed.), APHA-
AWWA-WEF, Pub: APHA, Washington, DC 20001-3710.
• FAO. (2001). The State of World Fisheries and Aquaculture 2001. FAO, Rome, Italy.
• Gill, J.J., Svircev, A.M., Smith, R., and Castle, A.J. (2003). Bacteriophages of Erwinia amylovora. Appl
Environ Microbiol., 69: 2133–2138.
• Giri, S.S., Sukumaran, V. and Oviya, M. (2013). Potential probiotic Lactobacillus plantarum VSG3
improves the growth, immunity, and disease resistance of tropical freshwater fish, Labeo rohita.
Fish Shellfish Immunol., 34(2): 660–666.
• Johansson, M.L., Quednau, M., Molin, G. and Ahrne, S. (1995) Randomly amplified polymorphic
DNA (RAPD) for rapid typing of Lactobacillus plantarum strains. Lett Appl Microbiol., 21: 155–159.
• Jun, J.W. (2013). Protective effects of the Aeromonas phages pAh1-CandpAh6-Cagainstmass
mortality of the cyprinid loach (Misgurnus anguillicaudatus) causedby Aeromonas hydrophila.
Aquaculture, 450: 416–417.
• Paterson, W. D., Douglas, R. J., Grinyer, I. and McDermott, L. A. (1969). Isolation and preliminary
characterization of some Aeromonas salmonicida bacteriophages. J. Fish. Res. Can., 26: 629–632.
• Saha, R. K. (2010). Soil and Water Quality Management for Sustainable Aquaculture (1sted.).
Narendra Publishing House, Delhi, pp. 33-186.
• Sambrook, J., Fritsch, E.F. and Maniatis, T. (1989). Molecular Cloning: A Laboratory Manual, 2nd
edn. Cold Spring Harbor, NY, USA: Cold Spring Harbor Laboratory Press.
• Silva, Y.J. (2016). Biological controlof Aeromonas salmonicida infection in juvenile Senegalese sole
(Solea senegalensis) with Phage AS-A. Aquaculture, 450: 225–233.
• Spencer, R. (1960). Indigenous marine bacteriophages. J. Bacteriol., 79 :614.
• Ackermann, H.W. (2012.) Bacteriophage electron microscopy. Adv Virus Res., 82: 1-32. doi:
10.1016/B978-0-12-394621-8.00017-0.
• Adams, M.H. (1959) Bacteriophages. New York, NY, USA: Interscience.
• APHA (2005).Standard Methods for the Examination of Water and Wastewater (21st ed.), APHA-
AWWA-WEF, Pub: APHA, Washington, DC 20001-3710.
• FAO. (2001). The State of World Fisheries and Aquaculture 2001. FAO, Rome, Italy.
• Gill, J.J., Svircev, A.M., Smith, R., and Castle, A.J. (2003). Bacteriophages of Erwinia amylovora. Appl
Environ Microbiol., 69: 2133–2138.
• Giri, S.S., Sukumaran, V. and Oviya, M. (2013). Potential probiotic Lactobacillus plantarum VSG3
improves the growth, immunity, and disease resistance of tropical freshwater fish, Labeo rohita.
Fish Shellfish Immunol., 34(2): 660–666.
• Johansson, M.L., Quednau, M., Molin, G. and Ahrne, S. (1995) Randomly amplified polymorphic
DNA (RAPD) for rapid typing of Lactobacillus plantarum strains. Lett Appl Microbiol., 21: 155–159.
• Jun, J.W. (2013). Protective effects of the Aeromonas phages pAh1-CandpAh6-Cagainstmass
mortality of the cyprinid loach (Misgurnus anguillicaudatus) causedby Aeromonas hydrophila.
Aquaculture, 450: 416–417.
• Paterson, W. D., Douglas, R. J., Grinyer, I. and McDermott, L. A. (1969). Isolation and preliminary
characterization of some Aeromonas salmonicida bacteriophages. J. Fish. Res. Can., 26: 629–632.
• Saha, R. K. (2010). Soil and Water Quality Management for Sustainable Aquaculture (1sted.).
Narendra Publishing House, Delhi, pp. 33-186.
• Sambrook, J., Fritsch, E.F. and Maniatis, T. (1989). Molecular Cloning: A Laboratory Manual, 2nd
edn. Cold Spring Harbor, NY, USA: Cold Spring Harbor Laboratory Press.
• Silva, Y.J. (2016). Biological controlof Aeromonas salmonicida infection in juvenile Senegalese sole
(Solea senegalensis) with Phage AS-A. Aquaculture, 450: 225–233.
• Spencer, R. (1960). Indigenous marine bacteriophages. J. Bacteriol., 79 :614.