Potomac horse fever isolates
The present invention discloses novel isolates of Neorickettsia risticii , compositions comprising such isolates, vaccines and methods for using such vaccines against Potomac Horse Fever.
1. An isolated Neorickettsia risticii ( N. risticii ) bacterium that is the N. risticii Oregon isolate having the ATCC deposit number PTA-11232.
2. A composition comprising an immunogenically effective amount of a N. risticii bacterium according to claim 1 and a carrier.
3. The composition of claim 2 , further comprising a different N. risticii isolate.
4. A vaccine comprising an immunogenically effective amount of a N. risticii bacterium according to claim 1 and a carrier;
wherein said vaccine reduces the incidence and severity of clinical Potomac Horse Fever disease in a horse when that horse is challenged with an N. risticii Oregon strain.