Submitted to: Pig Veterinary Society International Congress Proceedings
Publication Type: Proceedings
Publication Acceptance Date: March 30, 2010
Publication Date: July 18, 2010
Citation: Brockmeier, S., Loving, C.L., Mullins, M., Register, K.B., Nicholson, T.L. Prior Colonization with an Avirulent Haemophilus parasuis Isolate Prevents Disease from a Subsequent Virulent Challenge with a Heterologous Isolate. In: Proceedings of the Pig Veterinary Society International Congress, July 18-21, Vancouver, Canada. p. 192. Technical Abstract: Four groups of pigs were inoculated with a different isolate of Haemophilus parasuis intranasally (SW114, 12939, MN-H, and 29755), with a fifth group serving as sham inoculated controls. Three of the 4 isolates (12939, MN-H, and 29755) caused systemic disease, while the SW114 pigs remained healthy with no clinical signs of disease. The SW114 pigs were then rechallenged with the 12939 isolate to determine if they would be protected from a heterologous virulent strain. Three control pigs were also challenged with 12939. All three control pigs developed systemic disease, but all pigs previously challenged with SW114 remained healthy. Thus, heterologous protection using avirulent isolates is possible.