Fig 1.

Core genome-based phylogenetic tree for the isolates. The 52 genomes from our study are shown in bold. The other genomes were obtained from the study by Lebreton et al. (2). The genomes were assigned to one of the previously described clades—A1, A2, or B—highlighted in salmon, purple, and blue, respectively. In the outermost circle, the colored circles and triangles represent ampicillin susceptibility, determined by disk diffusion methods or extracted from previous publications. Gray circles represent missing values. The tree is mid-point rooted between clade B and non-clade B genomes. The scale represents genetic distances in nucleotide substitutions per site.