Isolation and characterisation of Vibrio alginolyticus lytic bacteriophage φVa-1 from brackishwater clam Meritrix meritrix in India

Abstract

The Gram negative bacterium Vibrio alginolyticus is generally found in marine and brackishwater systems. A lytic bacteriophage capable of specifically infecting V. alginolyticus was isolated from the brackishwater clam (Meretrix meretrix) using agar overlay technique. The phage produced plaques 3 mm in dia, which increased to 5 mm overnight on tryptone soya agar (TSA) plates and the optimum temperature and pH was found to be 32°C and 7.5 respectively. The phage was designated as φVa-1 and nucleic acid characterisation confirmed that the phage has double stranded DNA. Transmission electron microscopic observations revealed that the bacteriophage had hexagonal structure with a long contractile tail andthe phage was found to belong to the family Myoviridae.