Assessment of plasmid lateral transfer between representative B Assessment of plasmid lateral transfer between representative B. anthracis and pathogenic B. cereus strains carrying complete pXO1/pXO2-like plasmids. Assessment of plasmid lateral transfer between representative B. anthracis and pathogenic B. cereus strains carrying complete pXO1/pXO2-like plasmids. (A and B) Comparison of phylogenetic relationships based on the core genome for the chromosome and pXO1 (A) and for the chromosome and pXO2 (B) in strains carrying one or both plasmids. Phylogenetic reconstructions shown in panel A were based on the alignment of 210,123 variable positions found in the concatenated alignment of 4,233 core orthologous genes for the chromosome and 458 variable positions identified in the concatenated alignment of 149 pXO1 core orthologous genes. Phylogenetic relationships in panel B were constructed from the alignment of 74,389 variable positions found in the concatenated alignment of 4,616 core orthologous genes for the chromosome and 120 variable positions identified in the concatenated alignment of 88 pXO2 core orthologous genes. No signal of plasmid lateral transfer between the two phylogroups was apparent. Angela Pena-Gonzalez et al. mSystems 2018; doi:10.1128/mSystems.00065-18