Biocontrol of Foodborne Pathogen Salmonella Using Bacteriophage ΦEnt
Disciplines
Biology | Microbiology | Virology
Abstract (300 words maximum)
Salmonella is one of the most common causes of foodborne illness. To prevent Salmonella infection, it is imperative to control Salmonella in food systems. Using bacteriophages (phages) to control bacterial pathogens is a novel biocontrol method. The objectives of this project were to measure the growth kinetics of phage ΦEnt and to determine the efficacy of the phage as a biocontrol agent against Salmonella enterica serovar Thompson in a model food system (cucumber juice). The one-step growth curve of the phage was determined at the multiplicity of infection (MOI) of 0.02 in Tryptic Soy Broth at 37°C. The effectiveness of ΦEnt against Salmonella was evaluated at MOIs 1, 10, and 100 in cucumber juice at 37°C over a 5-hr period. Phage titer and host concentration were measured using plaque assay and the plate count method, respectively. One-step growth curve of the phage showed that its latent period and rise period were about 40 min and 30 min, respectively. The average burst size was 32 phage particles per infected cell. During the first 3 hours, phage infection only at an MOI of 100 completely inhibited the host growth in cucumber juice. Additional one-hour phage infection, regardless of the MOI, caused a rapid cell lysis resulting in greater than 3-log and 5-log reductions in host concentration compared with the initial and final host concentrations, respectively. These results show that phage ΦEnt is effective against Salmonella Thompson, suggesting that it is a good candidate as a biocontrol agent against Salmonella in food systems.
Academic department under which the project should be listed
CSM - Ecology, Evolution, and Organismal Biology
Primary Investigator (PI) Name
Jean Lu
Biocontrol of Foodborne Pathogen Salmonella Using Bacteriophage ΦEnt
Salmonella is one of the most common causes of foodborne illness. To prevent Salmonella infection, it is imperative to control Salmonella in food systems. Using bacteriophages (phages) to control bacterial pathogens is a novel biocontrol method. The objectives of this project were to measure the growth kinetics of phage ΦEnt and to determine the efficacy of the phage as a biocontrol agent against Salmonella enterica serovar Thompson in a model food system (cucumber juice). The one-step growth curve of the phage was determined at the multiplicity of infection (MOI) of 0.02 in Tryptic Soy Broth at 37°C. The effectiveness of ΦEnt against Salmonella was evaluated at MOIs 1, 10, and 100 in cucumber juice at 37°C over a 5-hr period. Phage titer and host concentration were measured using plaque assay and the plate count method, respectively. One-step growth curve of the phage showed that its latent period and rise period were about 40 min and 30 min, respectively. The average burst size was 32 phage particles per infected cell. During the first 3 hours, phage infection only at an MOI of 100 completely inhibited the host growth in cucumber juice. Additional one-hour phage infection, regardless of the MOI, caused a rapid cell lysis resulting in greater than 3-log and 5-log reductions in host concentration compared with the initial and final host concentrations, respectively. These results show that phage ΦEnt is effective against Salmonella Thompson, suggesting that it is a good candidate as a biocontrol agent against Salmonella in food systems.