Attenuated
The present invention provides attenuated P. multocida strains that elicit an immune response in animal P. multocida , compositions comprising said strains, methods of vaccination against P. multocida , and kits for use with such methods and compositions. The invention further provides novel, genetically-engineered mutations in P. multocida hyaD and nanPU genes, which are useful in the production of novel attenuated P. multocida bacterial strains.
1. A composition comprising an attenuated Pasteurella multocida ( P. multocida ) strain, wherein the composition comprises an effective amount of the strain to provide a safe and effective immune response in bovine against P. multocida or diseases caused by P. multocida , wherein the strain comprises deletions or partial deletions in its hyaD gene or homologs thereof having comparable function, which results in an inability to synthesize glycosyl transferase, nanPU gene or homologs thereof having comparable function, which results in an inability to add sialic acid residues to terminal lipooligosaccharides, or both genes, or homologs thereof having comparable function, relative to its virulent parental P. multocida strain; such that the attenuated strain exhibits reduced or no expression of the hyaD gene, the nanPU gene, or both, relative to the virulent parental strain.
2. The composition of claim 1 , wherein the strain, prior to deletion, comprised genes having at least 70% identity and comparable function to the sequences as set forth in SEQ ID NOs:1, 5, or both.
3. The composition of claim 2 , wherein the genes comprise nucleotides set forth in SEQ ID NOs:1 or 5.
4. The composition of claim 3 , wherein the strain expresses level(s) of HyaD and/or NanP, NanU peptide(s) that are significantly reduced or undetectable, relative to the strain's corresponding virulent parental strain.
5. The composition of claim 1 , characterized in that the strain has mutations in the same genes as does the strain deposited at the ATCC under the Patent Deposit Designation PTA-120624.
6. The composition of claim 5 , characterized in that the strain is the strain deposited at the ATCC under the Patent Deposit Designation PTA-120624.
7. The composition of any one of claims 1 to 6 , wherein the composition further comprises a pharmaceutically or veterinary acceptable vehicle, diluent or excipient.
8. The composition of claim 7 , wherein the composition further comprises an adjuvant.
9. The composition of claim 8 , wherein the adjuvant is inactivated bacteria, inactivated virus, fractions of inactivated bacteria, bacterial lipopolysaccharides, bacterial toxins, or combinations thereof.
10. The composition of claim 9 , wherein the composition is a vaccine composition that provides a protective immune response in bovine against virulent P. multocida challenge.
11. The composition of any one of claim 9 or 10 , wherein the composition further comprises at least one additional antigen associated with a bovine pathogen other than P. multocida.
12. The composition of claim 11 , wherein the at least one or more additional antigen(s) is capable of eliciting in a bovine an immune response against Foot-and-Mouth Disease Virus (FMDV) or Bovine Viral Diarrhea (BDV).