Isolation of Borrelia burgdorferi from Neotoma fuscipes, Peromyscus maniculatus, Peromyscus boylii, and Ixodes pacificus in Oregon

The number of Lyme disease cases in Oregon has increased in recent years de spite the fact that the pathogen, Borrelia burgdorferi, has never been isol ated in the state. Rodent and tick surveys were undertaken in 1997 to isola te and characterize strains of B. burgdorferi from Oregon and to identify p otential reservoirs and vectors of Lyme disease. Borrelia burgdorferi was i solated from Neotoma fuscipes, Peromyscus maniculatus, P. boylii, and Ixode s pacificus. Both N. fuscipes and P. maniculatus were infested with I. paci ficus and I. spinipalpis. Although I. pacificus infested P. boylii, I. spin ipalpis was not found on this rodent, and only 4% of the P. boylii were inf ected with B. burgdorferi compared with the 19% and 18% infection rates fou nd in N. fuscipes and P. maniculatus, respectively. Variation in the molecu lar weights of the outer surface proteins A and B were found in these first confirmed isolates of B. burgdorferi from Oregon, as well as truncated for ms of outer surface protein B.