International Symposium on Fisheries and Aquatic Sciences, Trabzon, Turkey, 24 - 26 October 2023, pp.36
Vibrio anguillarum is a type of marine bacteria that lives in estuaries and coastal marine areas all over the world. It is a significant fish pathogen because it causes vibriosis in both warm and coldwater fish species, resulting in large mortalities and economic losses in aquaculture. Antimicrobial therapy is applied to treat vibriosis following an outbreak. Antimicrobial resistance may develop in bacteria, therefore antimicrobial treatment may be ineffective. To overcome this kind of problem, alternative strategies should be developed. In the present study, the phenotype, kinetics, and genetics of three lytic phages, VP-11, VP-Bes, and VP- Ala, specific for V. anguillarum, Va-11, Va-Bes, and Va-Ala strains, were described. The latent period of all phages was between 30 and 50 minutes, and their bursting sizes ranged from 36 to 120 plaque-forming units (PFU) per infected cell. Almost all phages were able to withstand pH values ranging from 4 to 10 and temperatures ranging from -20 to 50°C. In addition, these phages exhibited lytic activity against their own host bacteria strains, but none exhibited lytic activity against other fish pathogenic bacteria. The RFLP analysis revealed that all vibrio phage genomes were resistant to the enzymes BamHI, HindIII, and EcoRI. Moreover, all phages contained DNA genomes with two strands. Vibriosis phages are safe and can be used to treat an V. anguillarum infection as part of a cocktail. Using a cocktail of these phages may also prevent the emergence of phage-resistant microorganisms.