Skip to main content
ARS Home » Southeast Area » Auburn, Alabama » Aquatic Animal Health Research » Research » Publications at this Location » Publication #410647
Research Project: Integrated Research to Improve Aquatic Animal Health in Warmwater Aquaculture

Location: Aquatic Animal Health Research

Title: Isolation and characterization of phage AhFM11 against hypervirulent Aeromonas hydrophila and its use in aquaculture as a therapeutant

Author
item MULIYA SANKAPPA, NITHIN - Oak Ridge Institute For Science And Education (ORISE)
item BOREGOWDA, KUSHALA - Karnataka Veterinary, Animal And Fisheries Sciences University
item KALLAPPA, GIRISHA - Karnataka Veterinary, Animal And Fisheries Sciences University
item Andersen, Linnea
item THANGAVEL, SURESH - Karnataka Veterinary, Animal And Fisheries Sciences University
item Abernathy, Jason

Submitted to: Aquaculture America
Publication Type: Abstract Only
Publication Acceptance Date: 11/20/2023
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Phages infecting hypervirulent Aeromonas hydrophila (vAh) had not been previously isolated; however, phages have been isolated against motile Aeromonas septicemia (MAS) with only a few of them having been characterized. This study aimed at developing therapeutic phage against hypervirulent Aeromonas hydrophila infection in aquaculture systems. A total of 110 water samples were collected aseptically. A novel phage AhFM11 specific to hypervirulent A. hydrophila was isolated and shows lytic activity against reference A. hydrophila (ATCC 35654). Soft agar overlay method was used to determine titer and found to be 1.58 x 1010 pfu/mL. Host range of the AhFM11 phage was performed for 131 Aeromonas spp. and 10 non Aeromonas. The results indicated that AhFM11 had a broad host range, infecting 65 Aeromonas species. Also, it was found that this phage did not harbor any antibiotic resistance genes. This is the first report of phage against hypervirulent A. hydrophila. Transmission electron microscopy (TEM) revealed that phage AhFM11 belongs to the family of Myoviridae. One-step growth curve of AhFM11 revealed that the phage has an average burst size of 276 ± 15 PFU per infected cell, adsorption rate of 97.3% and found to be stable in different environmental conditions. The AhFM11 genome comprised of 176,963 bp with an average G/C content of 41.5% (NCBI accession No. MZ450807.1). Bacteriophage-based strategies (injection, oral feed and immersion) to prevent and treat A. hydrophila infection were studied for the first time in India. Prophylactic application in injection, immersion and feed impregnated phages showed 100%, 95.11% and 93.11% survival over challenged untreated fish. These findings support that phage AhFM11 can be used to treat/control A. hydrophila infection in cultured fishes and has immense value as a potential alternative to antibiotics.