Genetic Analysis of the Flagella Gene of Lyme Disease Spirochetes ( Borrelia burgdorferi) Isolated from the Offshore Kinmen Island of Taiwan

Abstract

The flagella gene of Lyme disease spirochetes (Borrelia burgdorferi) was analyzed for the first time in Taiwan. The genetic identities of these Taiwan isolates (TWKM17) were clarified by comparing their sequence similarities and nucleotide distance values of the PCR-amplified flagella genes with three major genospecies of Lyme disease spirochetes for human infection and other zoonotic species of Borrelia spirochetes. Results from 26 isolates indicate that the sequence similarity of these Taiwan isolates revealed a highly homogeneous genotype, ranging from 99.3% to 100%, within the genospecies of B. burgdorferi sensu stricto and was distinguished from other genospecies of Borrelia isolates. Moreover, the nucleotide distance values performed by a pairwise distance calculation (Kimura 2-parameter distance) revealed a highly homogeneity ( 0.05) among other genospecies of spirochetes. The phylogenetic analysis also demonstrated that all these Taiwan isolates were closely related to the genospecies of B. burgdorferi sensu stricto within the same phylogenic group of B. burgdorferi sensu lato and can be clearly distinguished from other zoonotic species of Borrelia isolates. Thus, we conclude that all these Taiwan isolates should be classified into the genospecies of B. burgdorferi sensu stricto based on the genetic identity of the flagella gene.