Polymorphisms found in virulence-associated genes. The distribution of polymorphisms over the analyzed strains is shown. Within rows, polymorphisms are distinguished by color. BP1962 is part of RD10 which is deleted from ptxP3 strains (See Fig. 6). Deleted genes are indicated by "Δ". An overview of all known alleles is given in Additional file 5. Abbreviation: indel, insertion/deletion. References [16, 23, 28, 41, 42, 54–58].