IgY have been produced against opportunistic, invasive and toxin producing bacteria (Pseudomonas aeruginosa, Salmonella enteritidis and Staphyloccocus aureus respectively). The IgY asserted a growth inhibition effect on Pseudomonas aeruginosa, but did not prevent growth. Staphylococcus enterotoxin A production was suppressed, but not inhibited. Heat pasteurization at 65°C for 15 minutes of an IgY preparation against an E. coli toxin did not affect the neutralization activity of the antibody. Growth of E. coli is decreased in the presence of specific IgY against the bacteria, but no inhibition is seen with non-specific IgY.

Animals

Oral administration of spray dried yolk antibodies specific against Salmonella typhimurium or S. dublin was shown to prevent Salmonella infections in calves. The antibodies were administered three times a day for 7 to 10 days after inoculation with S. typhimurium or S. dublin. All calves in the control group died whereas only diarrhea and fever was observed in the group treated with the highest antibody titer. These antibodies gave protection against fatal salmonellosis. Yolk preparations from chickens immunized with purified outer membrane proteins, lipopolysaccharide, flagella and fimbriae of Salmonella has also been tested in mouse models of experimental salmonellosis. The mice treated with specific antibodies had a significantly higher survival rate than mice fed normal egg-yolk antibodies.

Humans

A mouth rinse containing egg yolk antibodies to Streptococcus mutans has been used to reduce the establishment of these bacteria in dental plaque of humans.The antibodies inhibited S. mutans adherence to saliva-coated hydroxyapatite discs in vitro and decreased the percentage of S. mutans per total streptococci in

vivo.