Bacteriophage potential against Vibrio parahaemolyticus biofilms

Vibrio parahaemolyticus constitutes an important foodborne pathogen frequently associated with seafood-borne illness. This bacterium can form biofilms on food and food contact surfaces during early stages of food processing, which makes it difficult to control using traditional methods. Consequently, new techniques to control its transmission via food are necessary. A promising option comprises lytic bacteriophages, which are viruses that can lethally infect a specific target host such as pathogenic bacteria and reduce their number. In this study, 34 phages specific to V. parahaemolyticus were isolated from surface water during September 2016 to October 2017. All phages were identified by transmission electron microscopy and their host ranges were evaluated. Among these, three phages belonging to different families were selected for further characterisation. One-step growth curve results showed that the three phages presented high burst sizes (458-593). The optimum thermotolerance, pH, and salinity concentration were 25-50 degrees C, 2.0-12.0, and 1.5-5.0%, respectively. The three selected phages and their phage cocktail were tested regarding the ability to prevent biofilm formation and to destroy established biofilms. The data demonstrated that the phages showed promise in preventing the development of V. parahaemolyticus biofilms. However, they were not effective in destroying established biofilms. The results highlight the potential of the three phages for biocontrol of V. parahaemolyticus in the aquaculture industry and as a preventive agent against biofilm formation in production lines.