Development of a gelatin/hyaluronic acid antimicrobial food pad containing the polyvalent bacteriophage STK8t

Foodborne pathogens such as Salmonella, Escherichia coli, Shigella, and Klebsiella pose considerable challenges to meat products. Current control methods involving chemicals and antibiotics raise concerns because of their potential effects on health and the environment, as well as the risk of antibiotic-resistant bacteria. To address this, we aimed to develop an antimicrobial film with enhanced absorption properties by incorporating a polyvalent bacteriophage (phage) into a gelatin/hyaluronic acid film. In this study, we isolated a polyvalent phage named STK8t and used it as an alternative biocontrol agent for food. Notably, it exhibited a potent lytic activity against Salmonella, E. coli, Shigella, and Klebsiella, showing its polyvalent properties with a wide host range. It showed a rapid antibacterial activity against S. Typhimurium and E. coli within 1 h and sustained a strong antibacterial ability against S. flexneri and K. pneumoniae for more than 11 h. STK8t-containing antibacterial films (GL2HA1) were developed by incorporating 1% (w/v) hyaluronic acid (HA) into 2% (w/v) gelatin (GL). Their swelling rate was significantly higher than that of the single GL film, and stable phage titers were maintained for up to 20 days. The GL2HA1 film strongly reduced the bacterial count of Salmonella by 6-log CFU/mL at 3 h. Additionally, it exhibited a remarkable improvement in beef drip absorption within 5 min compared with a conventional single-GL film. Therefore, these antibacterial systems show potential for broad applications in the food industry.