Isolation and characterization of Borrelia parkeri in Ornithodoros parkeri(Ixodida : Argasidae) collected in Colorado

This study describes the identification of Borrelia parkeri spirochetes in Colorado. Two isolates of B. parkeri (6230 and 6232) were recovered from Or nithodoros parkeri Cooley ticks collected at an inactive prairie dog town i n Moffat County. Both isolates were partially characterized by sequencing a nd subsequent parsimony and neighbor-joining analyses of appropriate region s of the 16S ribosomal RNA, flagellin and P66 genes. Analyses of the 16S ge ne sequences from the Colorado isolates indicated that they were more close ly related to B. parkeri and B. turicatae than to B. hermsii or the other s pecies of Borrelia investigated in this study. Additional analyses of amino acid sequences for flagellin and P66, however, clearly demonstrated that i solates 6230 and 6232 were most closely related to B. parkeri. The possible significance of B. parked as an agent of human disease is discussed.