Genetic relationships of O157:H7 isolates.

<p>(A): eBURST analysis of the O157:H7 sequence types. Majority of the STs belong to two clonal complexes which was defined based on one out 15 genes being different. Names after ST in brackets are strain names. The recently sequenced strains <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0036144#pone.0036144-Eppinger1" target="_blank">[22]</a> and their ST assignments are as follows: TW14588: ST23; EC4009, EC4127, EC4191, EC4401, EC4045, EC4076, EC869, 1125, FRIK2000, FRIK966: ST24; EC536: ST97; EC4486: ST110; EC4042: ST111; and LSU-61: ST112. (B). Genomic relationships of Xuzhou21 with other O157:H7 strains. The evolutionary relationship of the four genome sequenced strains of O157:H7 were determined using mutational SNPs. Allocation of SNPs to specific lineages were done using <i>E. coli</i> O55:H7 CB9615 as an outgroup <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0036144#pone.0036144-Zhou1" target="_blank">[48]</a>. Changes were shown in the boxes along the branches. Rec: recombination; sSNP: synonymous SNPs; nsSNP: non-synonymous SNPs. The lineages were defined based on the LSPA6 lineages <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0036144#pone.0036144-Laing1" target="_blank">[25]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0036144#pone.0036144-Yang1" target="_blank">[26]</a> and clades were based on Manning <i>et al.</i> SNP typing <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0036144#pone.0036144-Manning1" target="_blank">[2]</a>. (C): Genetic changes and relationships of the pO157 plasmids from the four strains. The bar at the top indicates coding genes in alternative colour with those transcribed in reverse direction pointing downwards. The key genes are marked above the bar. Changes in each plasmid are marked on branches on the left. Ins, del, nc, s, ns and large del denote single base insertion, single base deletion, non- coding SNP, sSNP, nsSNP, and large deletion respectively. The colours for the vertical lines on the grey strips are red for insertion, green for deletion and blue for other single base changes with shorter line for synonymous changes. The scale is in kb.