Active immunization using a siderophore receptor protein

Abstract

The invention provides a vaccine for immunizing poultry and other animals against infection by a gram-negative bacteria, and a method of immunizing an animal using the vaccine. The vaccine may contain purified siderophore receptor proteins derived from a single strain or species of gram-negative bacteria or other organism, which are cross-reactive with siderophores produced by two or more strains, species or genera of gram-negative bacteria. The invention further provides a process for isolating and purifying the siderophore receptor proteins, and for preparing a vaccine containing the proteins. Also provided is a method for diagnosing gram-negative sepsis.

1 - 45 . (canceled) 
   
   
       46 . A method comprising: administering to an animal a composition comprising gram-negative whole cells, wherein the gram-negative whole cells express siderophore receptor proteins on the cell surface, wherein the gram-negative whole cells lack outer oligosaccharide side chains of the lipopolysaccharide layer of the outer membrane, and wherein the administration results in an increased immune response to the siderophore receptor proteins. 
   
   
       47 . The method of  claim 46  wherein the gram-negative whole cell is  E. coli.    
   
   
       48 . The method of  claim 46  wherein the gram-negative whole cell is an avirulent R-mutant. 
   
   
       49 . The method of  claim 46  wherein the gram-negative whole cell is  E. coli  J5. 
   
   
       50 . The method of  claim 46  wherein the gram-negative whole cell is  Salmonella minnesota.    
   
   
       51 . The method of  claim 46  wherein the gram-negative whole cell is chemically altered to eliminate the outer oligosaccharide side chains. 
   
   
       52 . The method of  claim 46  wherein the gram-negative whole cell is a bacterin. 
   
   
       53 . A vaccine comprising gram-negative whole cells and an adjuvant, wherein the gram-negative whole cells express siderophore receptor proteins on the cell surface, and wherein the gram-negative whole cells lack outer oligosaccharide side chains of the lipopolysaccharide layer of the outer membrane. 
   
   
       54 . The vaccine of  claim 53  wherein the gram-negative whole cell is  E. coli.    
   
   
       55 . The vaccine of  claim 53  wherein the gram-negative whole cell is an avirulent R-mutant 
   
   
       56 . The vaccine of  claim 53  wherein the gram-negative whole cell is  E. coli  J5. 
   
   
       57 . The vaccine of  claim 53  wherein the gram-negative whole cell is  Salmonella minnesota.    
   
   
       58 . The vaccine of  claim 53  wherein the gram-negative whole cell is chemically altered to eliminate the outer oligosaccharide side chains. 
   
   
       59 . The vaccine of  claim 53  wherein the gram-negative whole cell is a bacterin.