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 - 34 . (canceled) 
     
     
         35 . A method for diagnosing a gram-negative bacterial infection in an animal, the method comprising:
 providing a solid support comprising at least one siderophore receptor protein (SRP) bound to the solid support, the SRP extracted from an outer membrane of a bacterium of family Enterobacteriaceae, family Pasteurellaceae, or family Pseudomonadaceae;   providing sample material obtained from an animal;   contacting the sample material with the bound SRP, wherein SRP-specific antibodies present in the sample material react with the bound SRP to form a complex; and   detecting the complex, wherein the presence of a detectable complex indicates the animal has or has had a gram-negative bacterial infection.   
     
     
         36 . The method of  claim 35  wherein the Enterobacteriaceae is  Escherichia coli  or  Salmonella  spp. 
     
     
         37 . The method of  claim 36  wherein the Enterobacteriaceae is  E. coli , and wherein the SRP has a molecular weight of about 89 kDa, about 84 kDa, about 78 kDa, about 74 kDa, or about 72 kDa. 
     
     
         38 . The method of  claim 36  wherein the Enterobacteriaceae is  Salmonella  spp., and wherein the SRP has a molecular weight of about 89 kDa, about 81 kDa, or about 72 kDa. 
     
     
         39 . The method of  claim 35  wherein the Pasteurellaceae is  Pasteurella  spp. 
     
     
         40 . The method of  claim 39  wherein the SRP has a molecular weight of about 96 kDa, about 84 kDa, or about 80 kDa. 
     
     
         41 . The method of  claim 35  wherein the gram-negative infection is caused by  Escherichia coli, Salmonella  spp.,  Pasteurella  spp., or  Pseudomonas  spp. 
     
     
         42 . The method of  claim 35  wherein the antibody is a first antibody, wherein the detecting comprises contacting the complex with a second antibody reactive with the first antibody. 
     
     
         43 . The method of  claim 35  wherein the sample material is blood or serum. 
     
     
         44 . The method of  claim 35  wherein the animal is domestic fowl, livestock, horses, companion animals, or human. 
     
     
         45 . A method of diagnosing a gram-negative bacterial infection in an animal, the method comprising:
 providing a sample material obtained from an animal;   immobilizing the sample material on a substrate;   contacting the immobilized sample material with an antibody immunoreactive with a siderophore receptor protein (SRP) to form an immobilized complex of the antibody and the SRP;   contacting the immobilized antibody/protein complex with a labelled antibody anti-species antibody reactive with the antibody of the immobilized antibody/protein complex; and   detecting the labeled antibody attached to the immobilized antibody/protein complex.