Thermal stability of bacteriophage that kills foodborne pathogen Shigella
Disciplines
Bacteriology | Food Microbiology | Microbiology | Virology
Abstract (300 words maximum)
Shigella are a group of bacteria that cause a foodborne illness called shigellosis. The disease is often acquired from consuming foods contaminated with Shigella. Most people with shigellosis have diarrhea (sometimes bloody), fever, and stomach cramps. It was estimated that each year Shigella cause 165 million cases and 1.1 million deaths globally. Controlling Shigella in foods is a key to prevent Shigellosis. Although many methods have been used to control Shigella in foods, all of them have limitations. It needs to develop alternative methods to effectively control of these pathogens in foods. Bacteriophages (phages) are viruses that kill bacteria. Phages have emerged as promising biocontrol agents against bacterial pathogens because they can cause rapid bacterial death, do not replicate in foods unless their bacterial hosts are present, do not infect humans and other animals, and do not alter food color, odor, taste, and nutritional value. This project evaluated the thermal stabilities of Shigella phage in Tryptic Soy Broth at various temperatures including 72°C. It was found that the phage was very stable at 50°C for at least 30 min. Heating at 63°C for 30 min caused 2 log reduction in phage concentration. Heating at 72°C for 15 sec (pasteurization condition) resulted in less than 1 log reduction in phage concentration, indicating that the phage survived well during pasteurization and can protect foods against post-heat contamination by Shigella. The Shigella phage showed high thermal stabilities and thus it has high potential to be used as biocontrol agents against Shigella in foods.
Academic department under which the project should be listed
CSM - Molecular and Cellular Biology
Primary Investigator (PI) Name
Jean Lu
Thermal stability of bacteriophage that kills foodborne pathogen Shigella
Shigella are a group of bacteria that cause a foodborne illness called shigellosis. The disease is often acquired from consuming foods contaminated with Shigella. Most people with shigellosis have diarrhea (sometimes bloody), fever, and stomach cramps. It was estimated that each year Shigella cause 165 million cases and 1.1 million deaths globally. Controlling Shigella in foods is a key to prevent Shigellosis. Although many methods have been used to control Shigella in foods, all of them have limitations. It needs to develop alternative methods to effectively control of these pathogens in foods. Bacteriophages (phages) are viruses that kill bacteria. Phages have emerged as promising biocontrol agents against bacterial pathogens because they can cause rapid bacterial death, do not replicate in foods unless their bacterial hosts are present, do not infect humans and other animals, and do not alter food color, odor, taste, and nutritional value. This project evaluated the thermal stabilities of Shigella phage in Tryptic Soy Broth at various temperatures including 72°C. It was found that the phage was very stable at 50°C for at least 30 min. Heating at 63°C for 30 min caused 2 log reduction in phage concentration. Heating at 72°C for 15 sec (pasteurization condition) resulted in less than 1 log reduction in phage concentration, indicating that the phage survived well during pasteurization and can protect foods against post-heat contamination by Shigella. The Shigella phage showed high thermal stabilities and thus it has high potential to be used as biocontrol agents against Shigella in foods.