ACTIVE IMMUNIZATION USING A SIDEROPHORE RECEPTOR PROTEIN
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.