Figure 1. Phylogenetic relationship of the tetM sequences of Streptococcus suis. An unrooted maximum-parsimony tree was based on multiple aligned partial tetM sequences of 2 S. suis (asterisk) and 53 reference sequences retrieved from GenBank. The alignment length for the analysis was 1,415 bp. If available, the designation of the tetM-carrying plasmid or transposon is indicated, followed by the GenBank accession number. Percent bootstrap support at each internal node was based on 200 replicate trees. The sequences of known pig origin are marked in red.