PHYLOGENESIS OF RELAPSING FEVER BORRELIA SPP

The phylogenetic relationships of 20 relapsing fever (RF) Borrelia spp , were estimated on the basis of the sequences of rrs genes. Complete sequences were aligned and compared with previously published sequence s, and the similarity values were found to be 97.7 to 99.9%. Phylogene tic trees were constructed by using the three neighbor-joining, maximu m-parsimony, and maximum-likelihood methods. The results of the compar ative phylogenetic analysis divided the RF Borrelia spp. into three ma jor clusters, One cluster included Borrelia crocidurae, Borrelia dutto nii, Borrelia recurrentis, and Borrelia hispanica. Another cluster com prised two main branches with Borrelia coriaceae, Borrelia lonestari, and Borrelia miyamotoi on one side apd Borrelia parkeri, Borrelia turi catae, and Borrelia hermsii on the other side. Borrelia anserina const ituted the third cluster. The phylogenetic position of Borrelia persic a was mote uncertain. These results suggested that the taxonomy of the se spirochetes should be revised, To overcome the problems of culturin g the spirochetes, RF Borrelia primers were defined. Following PCR amp lification of the rrs gene, restriction length fragment polymorphism c ould be used to distinguish between RF Borrelia strains.