Isolation and characterization of Salmonella enteritidis bacteriophage Salmp-p7 isolated from slaughterhouse effluent and its application in food

Salmonella enteritidis is one of the most common pathogens that cause foodborne disease outbreaks and food spoilage, which seriously threatens human health. Bacteriophages have shown broad application prospects in controlling harmful microorganisms during food processing and preservation due to their ability to specifically infect bacteria. In this study, Salmonella enteritidis bacteriophage Salmp-p7 was isolated and characterized from slaughterhouse wastewater. Transmission electron microscopy (TEM) analysis showed that Salmp-p7 belonged to the Siphoviridae family and was active against Salmonella enteritidis and Escherichia coli. Whole genome sequence analysis showed that Salmp-p7 was a lytic bacteriophage with a total length of 60,066 bp of sequence. Salmp-p7 has a short incubation period and a long burst duration, with a burst volume of 55 PFU/cell and a good lysis effect. It can maintain a stable state within the temperature range of 30–60℃ and pH range of 4–12 and has the potential for application in food. In vitro, antimicrobial curves and inhibition of biofilm removal experiments showed that Salmp-p7 could effectively inhibit and eliminate Salmonella enteritidis. The application of Salmp-p7 to the whole liquid of infected eggs resulted in a significant reduction of viable bacteria. And Salmp-p7 has high stability and lytic activity and has the potential to become a new biological control agent for Salmonella enteritidis in eggs.