R2 ¼ coefficient of determination of linear
regression. N/A ¼ Not Applicable. NL ¼ Not Listed. BAA isolates are part of the ATCC MP-9 collection. Presence (þ) or absence () of the Shiga toxin 1 (stx1), Shiga toxin 2 (stx2),
intimin (eae), or hemolysin (ehxA) genes which are involved in STEC virulence are listed.