FIG 1.
Population structure of E. coli, highlighting CCs and STs associated with all four Shigella species and with EIEC. Isolates are colored with respect to their identification by traditional biochemistry and serology (yellow, S. sonnei; blue, S. flexneri; green, S. boydii; red, S. dysenteriae; pale blue, EIEC; and white, E. coli), and anomalies are labeled. (A) Misidentified as S. boydii by traditional tests because of a nonfunctional wzx1–5 gene. (B) Part of CC288 (a CC comprising mostly S. dysenteriae isolates) but biochemically and serologically identified as S. boydii. (C) Biochemically and serologically identified as S. boydii. (D) Belongs to ST243 (an ST comprising S. boydii and S. flexneri serotype 6) but biochemically and serologically identified as S. dysenteriae. (E) Identified as EIEC by biochemistry, serology, and PCR.