FIG. 2.

Phylogenetic tree determined from the DNA sequences of rrf-rrl intergenic spacer amplicons of southern strains of B. burgdorferi sensu lato. The neighbor-joining tree is constructed with PAUP software and is based on a comparison of 258-bp nucleotides of the rrf-rrl intergenic spacer sequence. The tree was compared with the trees produced by the maximum-likelihood and parsimony methods and the unweighted pair group method with arithmetic averages methods with PAUP software. The four methods produced similar results. The scale bar represents the calculated distance value.