Patent 7932085 was granted and assigned to University of Guelph on April, 2011 by the United States Patent and Trademark Office.
The present invention provides nucleic acid sequences encoding a modified leukotoxin protein, wherein the modification comprises the removal of nucleic acid sequences encoding amino acids within hydrophobic transmembrane domains of full length leukotoxin protein, preferably from Mannheimia haemolytica. The modified leukotoxin proteins are useful in vaccine compositions effective against Mannheimia haemolytica in animals.