USE OF A 35.5 KDA CELL-MEMBRANE COMPOSITION OF PASTEURELLA-MULTOCIDA AND AN ANTIIDIOTYPE ANTIBODY TO INDUCE PROTECTIVE IMMUNITY IN LEGHORN CHICKENS

Using polyacrylamide gel electrophoresis and Western blot analysis, a 35.5 kDa cell membrane composition of Pasteurella multocida ATCC 11039 was identified as a dominant epitope of the bacterium. Mice inoculate d with inactivated whole bacteria produce antisera primarily reactive with the 35.5 kDa component (Pm 35.5) in Western blot analysis. The ou ter membrane component was composed primarily of protein but did have lipopolysaccharide present at 133 mu g mg(-1) protein. In challenge tr ials (Trial 2), groups of white leghorn chickens vaccinated with Pm 35 .5 or an anti-idiotypic antibody (using Pm 35.5 as the original antige n) had significant difference in mortality of 3.2% and 48.3%, respecti vely, when compared with unvaccinated controls (99%). Mortality in a g roup of chickens receiving a commercially available bacterin (9.2%) wa s higher but not significantly different from the mortality of the Pm 35.5 vaccinated group (3.2%).