Fig. 1: Global phylogenetic analysis and genomic characterization of B. melitensis lineages.

A Whole-genome SNP-based phylogenetic tree of the global B. melitensis isolates, comprising 747 publicly available genomes and 103 isolates sequenced from Yunnan Province, China. The tree was plotted using Grafen’s transformation, showing topological relationships. The isolates in major lineages and sub-lineages are distinguished by colors. Outer rings indicate the geographic region (continent and area) and date of sampling. Isolates in this study were marked. B Geographic distribution of B. melitensis isolates included in this study. Countries are shaded according to the total number of isolates collected. The circles represent the proportion of lineages in each area, with circle size proportional to the total number of isolates. Colors of the circles indicate different lineages. C Relationship between sample size and Shannon entropy of lineage distribution across geographic areas. Areas with above-average diversity are shown in yellow, and others in gray. D Power-law regression analysis based on the association between the number of genomes and new genes on the log scale, with shaded areas representing the 95% confidence intervals. E Relationship between pairwise evolutionary time and gene family copy number variation. The median estimates of the regression (50th percentile) and the 95% confidence interval were marked.