Oral treatment with bacteriophages reduces the concentration ofSalmonellaEnteritidis PT4 in caecal contents of broilers

Bacteriophages isolated from free-range chickens were tested as a therapeutic agent for reducing the concentration of Salmonella enterica serovar Enteritidis phage type 4 (S. Enteritidis PT4) in caeca of broilers. One-day-old broilers infected with S. Enteritidis PT4 by a seeder bird method were orally treated on the seventh day of age with a mixture of 10(11) plaque-forming units of each of three bacteriophages. Five days after treatment the bacteriophage-treated group showed a reduction of 3.5 orders of magnitude on colony-forming units of S. Enteritidis PT4 per gram of caecal content. Samples collected at 10, 15, 20 and 25 days after treatment revealed that treated birds still had lower colony-forming units of S. Enteritidis PT4 per gram of caecal content. These data gave us compelling evidence that a mixture of bacteriophages may be efficacious in reducing S. Enteritidis PT4 concentration in broilers' caeca and therefore reducing contamination of poultry products by this food-borne pathogen.