Graphic representation of spacers grouped into patterns from CRISPR arrays CR2 and CR3 of the 85 <i>E. amylovora</i> strains examined in this study.

<p>Hosts of <i>E. amylovora</i> strains harboring the respective spacer patterns shown are listed on the left. Individual spacer sequences are represented by boxes; spacers were considered unique if they contained >5 nucleotide differences compared to other spacer sequences. Each unique spacer (588 identified in this study) was assigned a number. Spacers of similar color shown in the same columns under the same number are identical. Empty areas indicate the corresponding spacer in other similar patterns is not present. Open boxes refer to spacers that were only detected once in the collection. Spacers shaded grey and boxed in red are spacers found in both CR1 and CR2 arrays, while spacers shared between <i>Rubus</i> strains are shaded in yellow or in dark blue. The following spacer patterns were predominantly isolated from <i>E. amylovora</i> strains from apple and pear isolated in the Midwest, eastern U.S., and Canada (CR2: patterns 21–28) and in the western U.S. (CR2: patterns 29, 32, and 34).