Condensed dendrogram of unique Arcobacter STs. For each unique ST, the profile allele sequences were extracted and concatenated. The concatenated allele sequences were aligned using CLUSTAL X (ver. 2.0.5). The dendrogram was constructed using the neighbor-joining algorithm and the Kimura two-parameter distance estimation method. Bootstrap values of >75%, generated from 500 replicates, are shown at the nodes. The scale bar represents substitutions per site. The tree is rooted to C. jejuni strain NCTC 11168. The A. halophilus strain LA31B concatenated sequence was extracted from the draft A. halophilus genome. 'Group 1' A. cryaerophilus sequence types include: ST-209, ST-220, ST-221, ST-231, ST-232 and ST-270.