Escherichia coli O157:H7 Shiga Toxin-Encoding Bacteriophages: Integrations, Excisions, Truncations, and Evolutionary Implications

Volume 185, no. 12, p. 3596-3605. Page 3597: Table 1 erroneously designated wrbA as being occupied by a bacteriophage in the sorbitol-fermenting strains CB2755 and 493/89, whereas it is, in fact, intact (as demonstrated in Fig. 1). Therefore, the stx₂ bacteriophage integrated into a site or sites other than wrbA in these isolates. Thus, our assumptions that these sorbitol-fermenting organisms diverged from other members of the STEC1 lineage after the stx₂ bacteriophage integrated into wrbA and that integration of the stx₂ bacteriophage into wrbA is an ancestral event are not supported by the data. The corrected data, which suggest that the stx₂ bacteriophage inserted into wrbA at a later point in the evolution of the STEC1 clade after a truncated bacteriophage was acquired by Escherichia coli O157:H7, lead to a simpler evolutionary scenario which obviates the need to invoke lineages A, B, and C (see the revised Fig. 4 shown below).

FIG. 4.

Proposed evolutionary scenario for the STEC1 clade. Boxes represent organisms known to exist today. The circle represents a proposed intermediate organism between E. coli O55:H7 and E. coli O157:H7.

Page 3600: The stx₁A and stx₁B labels in Fig. 2 were reversed.

Page 3603: Figure 4 and its legend should appear as shown below. .