Isolation and Efficacy Evaluation of Virulent Bacteriophages Specific to Fish Pathogenic Bacterium, Flavobacterium columnare

Abstract

Prasad, Y., Aparna, Kumar, D. 2010. Isolation and efficacy evaluation of virulent bacteriophages specific to fish pathogenic bacterium, Flavobacterium columnare. J. Appl. Anim. Res., 38: 169–172.

To develop phage therapy in freshwater aquaculture against antibiotic resistant bacterial pathogen, nine lytic bacteriophages (FCP1—FCP9) specific to fifteen isolates of Flavobacterium columnare (FC) were isolated from water and bottom sediments of pond, river and sewage canal of Sub-Himalayan region, India. The FCP1 exhibited broader host range as purified one conferred clear lytic plaques in the lawn of 9 out of 15 (60%) isolates of F. columnare at 25±2C and pH 7.0 to 10.0. The eclipse, latent period and burst size of FCP1 was10, 20 min and 370 virions/infected cell, respectively. It was specific to F. columnare only. Isolated F. columnare phages were made of hexagonal head and non contractile long tail belonging to family Podovariedae, a member of DNA virus. Results provide strong evidence of antibacterial nature of FCP1 phage and hence phage therapy employing it may be suitable to control F. columnare infection in fish hatchery and culture system.

Key words:

• Bacteriophage
• columnaris disease
• Flavobacterium columnare
• phage therapy