Fig. 1

Spacer composition of the CRR1 of sequenced cosmopolitan strains of E. amylovora. Numbering of the spacers is coherent with the one proposed earlier (Rezzonico et al. 2011), with the first digit corresponding to the number of the CRR followed by a three-digit number that increases from the most ancient to the more recent spacers (3′ to 5′ direction in the DNA). Sixteen different genotypes were recorded, which could be divided into three different groups (A-derived, D-derived, other) depending on the archetypal genotype from which they are probably originating. Spacer 1029 is highlighted in red, while the position of the C1f04/C1r09 primers developed to verify its number of copies via PCR is indicated by the arrows. It is worth to note that even if the Y genotype clearly evolutionarily belongs to the A-derived group, it would result in no amplification in the PCR assay due to the absence of spacer 1030 that is the annealing site of primer C1f04. For the purpose of our study, this genotype and related strain ACW65131 were nevertheless assigned to the A-derived genotypes to which they clearly belong. One typical representative for each genotype, including geographical origin and year of isolation, is listed hereafter. A: CFBP 1252 (UK 1958), B: Ea273 (USA 1971), C: Ea02 (CH 2002), E: Ea153 (USA 1989), F: Ea263 (IL 1997), Y: ACW65131 (CH 2009), Z: K18 (KZ 2013), Ƃ: KBE1 (RU 2009), ж: Tk86 (TK 2007), D: Ea 1/79 (DE 1979), W: FAW612 (CH 2001), X: ACW65131 (CH 2009), Д: TE4 (RU 2007), Є: VGE1 (RU 2010),, З: Ea2 (IR 2010), г: Tk119 (TK 2011)