With worldwide concern over the use of
antibiotics in animal agriculture and their contribution to the spread of antibiotic resistance, alternatives to conventional
antibiotics are needed. Previous research in our laboratories has shown that
colicin E1 is effective against some Escherichia coli strains responsible for postweaning
diarrhea (PWD) in vitro. In this study we examined the efficacy of the dietary inclusion of
colicin E1 in preventing experimentally induced PWD caused by F18-positive enterotoxigenic E. coli in young pigs. Twenty-four weaned pigs (23 days of age), identified by genotyping to be susceptible to F18-positive E. coli
infections, were individually housed and fed diets containing 0, 11, or 16.5 mg
colicin E1/kg diet. Two days after the start of the trial, all animals were orally inoculated with 1 x 10(9) CFU of each of two F18-positive E. coli strains isolated from pigs with PWD. The dietary inclusion of
colicin E1 decreased the incidence and severity of PWD caused by F18-positive enterotoxigenic E. coli and improved the growth performance of the piglets. Additionally, the reduced incidence of PWD due to dietary
colicin E1, lowered the levels of expression of the genes for
interleukin 1beta and
tumor necrosis factor beta in ileal tissues from these animals. The dietary inclusion of
colicin E1 may be an effective alternative to conventional
antibiotics in the diets of weaning pigs for the prevention of PWD caused by F18-positive enterotoxigenic E. coli.