BACKGROUND: Egg yolk antibody (IgY) is a unique type of immunoglobulin found in egg yolks, andmany reports have described
its ability to inhibit corresponding antigen bacteria. The objective of this study was to evaluate the antibacterial activity of IgY
specific to Listeria monocytogenes, an important food pathogen to both humans and animals, as well as its potential use for
food preservation.
RESULTS: Specific IgY was generated by immunising Leghorn chickens with whole cells of L. monocytogenes, and its inhibitory
effect on bacterial growth was tested in liquid medium and food samples. After 8 h of incubation with specific IgY, there was a
significant decrease in the growth (absorbance at 600 nm) of L. monocytogenes in comparison with controls. IgY also inhibited
the growth of L. monocytogenes inoculated onto fresh or smoked salmon samples. Compared with those of blanks, numbers of
L. monocytogenes were reduced by more than 2 log units after 15 days of storage at 6 ± 1 ◦
C in the presence of specific IgY.