Serotypes with deletions of the Cas machinery.

1The coordinates of the deleted regions of isolates with type A CRISPR structure and those of isolates with type F CRISPR structure are based on S. enterica serotype Typhimurium strain LT2 (GenBank AE006468) and serotype Typhi strain Ty2 (GenBank AE014613) genomes, respectively. The reverse primers used for these isolates are indicated in Table 2.2The cas3 gene of serotype Typhimurium LT2 strain is 2663 bp in size, whereas that of serotype Typhi strain Ty2 is 2207 bp in size, due to a frameshift leading to a premature stop codon. The sizes of the cas3 gene remnant are shown in brackets, not taking into account the serotype Typhi-specific frameshift.