Figure 1

Dendrogram based on relationships obtained from PCA analysis of the ICMS spectra. (A) Global cluster analysis of C. jejuni isolates. B1-3: Enlargement of major clusters, the overall majority of isolates is positive for the marker genes cj1365c, cj1585c, cj1321-6, fucP, cj0178, and cj0755 positive but dmsA-, ansB- and ggt-negative (different shades of yellow); B1: one cluster of dmsA⁺, ansB⁺ but ggt^-C. jejuni isolates in subtree Ia and a second cluster of dmsA⁺, ansB⁺ but ggt^-C. jejuni isolates in subtree Ib (blue & violet); cluster of CC 53 & CC 61 isolates with the dimeric form of the formic acid specific chemotaxis receptor Tlp7_m+c (beige); cluster of Tlp7_m+c⁺ CC 21 isolates – all of bovine origin (orange); B2: small cluster of dmsA⁺ and cstII⁺ isolates belonging to MLST-CC 1034 (teal) B3: The cluster of ggt⁺ isolates splits in two subclusters, which differ in cj1365c and cstII (dark and light blue). The relatedness of C. jejuni isolates in the ICMS spectra-based PCA-tree reflects the isolates subgroup affiliation & MLST CC/ST.