Isolation of Vibrio harveyi bacteriophage with a potential for biocontrol of luminous vibriosis in hatchery environments

A double stranded DNA bacteriophage of Vibrio harveyi was isolated from shrimp farm water from the west coast of India. The isolated phage belonged to the family Siphoviridae. Its broad lytic activity against V. harveyi isolates both from the west and east coast of India suggested that it had a potential for biocontrol of luminous vibriosis due to V. harveyi in aquaculture systems. Microcosm studies with Penaeus monodon larvae infected with V. harveyi showed that larval survival in the presence of bacteriophage was enhanced (80%) as compared with the control (25%). Field trials were conducted in a commercial hatchery where there was a natural outbreak of luminous bacterial disease. Treatment with bacteriophage improved larval survival and brought about decline in luminescent V. harveyi counts in hatchery tanks. It could hence be concluded that the bacteriophage had a potential for biocontrol of V. harveyi in hatchery settings.