Fig. 1

The phylogenetic relationships among GBS strains from different CC groups. On the left is the phylogenetic tree of 70 GBS strains, which was constructed with 1,000 bootstrap replications and rooted by outgroup. On the right is the information about strain host, serotype and ST. The major clonal complexes (CC) 1, 10, 17, 19, 23, 67, 102 and 552, which were defined by GBS MLST website (http://pubmlst.org/sagalactiae/), were all separated by distinct branches. H, Homo sapiens. B, Bos Taurus. F, fish. C, Canis lupus familiaris. T, Tursiops. adhP, pheS, atr, glnA, sdhA, glcK and tkt are the names of 7 allelic genes in MLST analysis, and below are the numbers of each allelic gene in MLST website. The colors (or absence of color) are used to emphasize certain regions of the chart