Phage Therapy To Reduce PreprocessingSalmonellaInfections in Market-Weight Swine

Abstract

Contamination of meat products with food-borne pathogens usually results from the carcass coming in contact with the feces of an infected animal during processing. In the case of Salmonella, pigs can become colonized with the organism during transport and lairage from contaminated trailers and holding pens, resulting in increased pathogen shedding just prior to processing. Increased shedding, in turn, amplifies the likelihood of carcass contamination by magnifying the amount of bacteria that enters the processing facility. We conducted a series of experiments to test whether phage therapy could limit Salmonella infections at this crucial period. In a preliminary experiment done with small pigs (3 to 4 weeks old; 30 to 40 lb), administration of an anti-Salmonella phage cocktail at the time of inoculation with Salmonella enterica serovar Typhimurium reduced Salmonella colonization by 99.0 to 99.9% (2-to 3-log reduction) in the tonsils, ileum, and cecum. To test the efficacy of phage therapy in a production-like setting, we inoculated four market-weight pigs (in three replicates) with Salmonella enterica serovar Typhimurium and allowed the challenged pigs to contaminate a holding pen for 48 h. Sixteen naïve pigs were randomly split into two groups which received either the anti-Salmonella phage cocktail or a mock treatment. Both groups of pigs were comingled with the challenged pigs in the contaminated pen. Treatment with the anti-Salmonella phage cocktail significantly reduced cecal Salmonella concentrations (95%; P < 0.05) while also reducing (numerically) ileal Salmonella concentrations (90%; P ‫؍‬ 0.06). Additional in vitro studies showed that the phage cocktail was also lytic against several non-Typhimurium serovars.

Bacteriophage cocktail and multi-strain probiotics in the feed for weanling pigs: effects on intestine morphology and targeted intestinal coliforms and Clostridium

“…Most of the previous studies on bacteriophages evaluated their therapeutic effects on disease challenged pigs (Barrow, 2001;Jamalludeen et al, 2009;Wall et al, 2010) only against one pathogen bacteria, but in the current experiment the bacteriophage cocktail included ten different bacteriophages against Salmonella, Coliforms, Streptococcus and Clostridium. The application of a bacteriophage cocktail can be a better way to prevent the proliferation of pathogens in gut microflora to avoid incidence of diarrhea and other related diseases.…”

Phages as Therapeutic Tools to Control Major Foodborne Pathogens: Campylobacter and Salmonella

“…(Borie et al, 2008;Borie et al, 2009) chicken Reduction of up to marginal levels in the ileum and six fold in the caeca in the Salmonella counts (Toro et al, 2005) chicken Reduction of up to 6 log 10 in simulated crop environment / 55% in recovery from caecal tonsils of chicks (Andreatti Filho et al, 2007) pig Reduction of up to 3 log 10 reduction of Salmonella colonization (Wall et al, 2010) …”

“…Recently, Wall et al (2010) tested the efficacy of a cocktail to treat S. Typhimurium experimentally infected pigs shortly before processing in order to reduce carcass contamination. Administration of the phage at the time of infection resulted in a 2-3 log 10 reduction of Salmonella colonization (Wall et al, 2010).…”

“…Administration of the phage at the time of infection resulted in a 2-3 log 10 reduction of Salmonella colonization (Wall et al, 2010). O'Flynn et al, (2006) isolated two broad host range Salmonella phages (st104a and st104b) which were partially resistant to the porcine gastric juice (pH 2.5).…”

Lytic Bacteriophages as Biocontrol Agents of Foodborne Pathogens

“…is also one of the principal causes of food-borne diseases causing diarrhea worldwide and is commonly found in chickens, turkey, pigs etc. Wall et al (2010) investigated the efficacy of phage mixture in reducing S. typhimurium colonization of pigs during their transportation and prior to being slaughtered. The researchers administered phages orally and in microencapsulated form that led to efficient reduction in Salmonella typhimurium contamination of ileum, cecum and tonsils of pigs.…”