Efficacy of bacteriophages killing foodborne pathogen Shigella in a model food system
Abstract (300 words maximum)
Shigella are gram-negative bacteria that can cause the foodborne illness known as shigellosis. Shigella are highly infectious and spread easily via the fecal-oral route. 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.
It is challenging to control Shigella in foods. Many methods currently used are either ineffective or change food characteristics. Alternative and better methods are needed to control of the pathogens in foods.
Bacteriophages (phages) have emerged as promising biocontrol agents against bacterial pathogens. Phages are viruses that kill target bacteria. They do not infect humans and other organisms. In addition, phages do not alter food color, odor, taste, and nutritional value. Furthermore, phages do not replicate in foods unless their bacterial hosts are present.
We evaluated the effectiveness of phage infection against Shigella at 37°C in cucumber juice as a model food system at different multiplicity of infections (MOIs). It was found that phiShig-L infection at MOI 1, 10, and 100 caused 5-log (99.999%) reduction in host concentration within 3, 2.5, and 1 hr, respectively, compared to the initial cell concentration. Slightly different from phiShig-L, phiShig-Tf infection took an additional hour to achieve the same reduction in cell concentration under these conditions. These data showed that the phage infection is highly effective to kill off the host cells within 4 hr, indicating that both phages have high potential to be used as biocontrol agents against Shigella in foods.
Efficacy of bacteriophages killing foodborne pathogen Shigella in a model food system
Shigella are gram-negative bacteria that can cause the foodborne illness known as shigellosis. Shigella are highly infectious and spread easily via the fecal-oral route. 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.
It is challenging to control Shigella in foods. Many methods currently used are either ineffective or change food characteristics. Alternative and better methods are needed to control of the pathogens in foods.
Bacteriophages (phages) have emerged as promising biocontrol agents against bacterial pathogens. Phages are viruses that kill target bacteria. They do not infect humans and other organisms. In addition, phages do not alter food color, odor, taste, and nutritional value. Furthermore, phages do not replicate in foods unless their bacterial hosts are present.
We evaluated the effectiveness of phage infection against Shigella at 37°C in cucumber juice as a model food system at different multiplicity of infections (MOIs). It was found that phiShig-L infection at MOI 1, 10, and 100 caused 5-log (99.999%) reduction in host concentration within 3, 2.5, and 1 hr, respectively, compared to the initial cell concentration. Slightly different from phiShig-L, phiShig-Tf infection took an additional hour to achieve the same reduction in cell concentration under these conditions. These data showed that the phage infection is highly effective to kill off the host cells within 4 hr, indicating that both phages have high potential to be used as biocontrol agents against Shigella in foods.