CHICKEN EGG-YOLK ANTIBODIES AGAINST F18AB FIMBRIAE OF ESCHERICHIA-COLI INHIBIT SHEDDING OF F-18 POSITIVE ESCHERICHIA-COLI BY EXPERIMENTALLYINFECTED-PIGS

F18ab and F18ac are antigenic variants of a colonizing fimbria commonl y found on E. coli associated with postweaning diarrhea and edema dise ase in pigs. Chicken F18ab antibodies were obtained by immunising hens with purified F18ab fimbriae. For their in vitro characterisation ant ibodies were isolated from diluted egg yolks by ammonium sulfate preci pitation. In vitro adhesion tests demonstrated that the chicken F18ab antibodies inhibited attachment of F18ab positive E. coli bacteria to the intestinal mucosa. Just weaned piglets were experimentally infecte d with an F18ab positive edema disease strain of E. coli, or with an F 18ac positive postweaning diarrhea E. coli strain. The animals were in fected on the second day of a period during which chicken F18ab antibo dies were added to their feed. During the same period, pigs of the con trol group received commercial eggs in which no F18 antibodies were de tected. In both experimental infections the excretion of the F18 posit ive strain was reduced in pigs that received the F18ab antibodies as c ompared to the control animals. The F18ab antibodies diminished the ca ses of diarrhea and death in animals infected with F18ac positive E. c oli.