Clusters of orthologous (COG) annotation, enrichment analysis, and genomic islands. (A) The functions are arranged according to the number of genes related to that function. The top five functional categories are “Function unknown”, “Replication/recombination and repair”, “Cell wall/membrane/envelop biogenesis”, “Amino acid transport and metabolism”, and “Transcription”. (B) Comparison of the core genome of all strains (130) and core genome of all the phylogroups. (C) Enrichment analysis of all subsections of the pan-genome was performed. Only persistent genome expressed enrichment in different pathways. The enrichment was related to pathways such as intracellular anatomical structure, cytoplasm, cytosol, and protein-containing complex, etc.