TABLE 3.

stx genes in 173 STEC isolates and other characteristics of the strains

stx gene(s)Total no. of strains (n = 173)No. of strains possessing the indicated characteristic (%):
O157 (n = 111)Non-O157 (n = 62)eae positive (n = 151)eae negative (n = 22)Ehly positive (n = 144)Ehly negative (n = 29)
stx128 (16)1a (1)27 (44)26 (17)2 (9)27 (19)1 (3)
stx1 and stx2c6 (3)5 (5)1 (2)6 (4)0 (0)5 (3)1 (3)
stx1 and stx21 (1)1 (1)0 (0)1 (1)0 (0)1 (1)0 (0)
stx1 and stx2vhb2 (1)2 (2)0 (0)2 (1)0 (0)1 (1)1 (3)
stx1, stx2, and stx2vhb1 (1)1 (1)0 (0)1 (1)0 (0)0 (0)1 (3)
stx2 and stx2c72 (42)71a (64)1 (2)71 (47)1 (5)72 (50)0 (0)
stx236 (21)21 (19)15 (24)35 (23)1 (5)28 (19)8 (28)
stx2c9 (5)3 (3)6 (9)3 (2)6 (27)3 (2)6 (21)
stx2vhb5 (3)3 (3)2 (3)3 (2)2 (9)3 (2)2 (7)
stx2 and stx2vhb3 (2)1 (1)2 (3)1 (1)2 (9)2 (1)1 (3)
stx2d-Ount2 (1)0 (0)2 (3)0 (0)2 (9)2 (1)0 (0)
Undigestibleb3 (2)0 (0)3 (5)0 (0)3 (14)0 (0)3 (10)
Weak positive strainsc in PCR for stxb3 (2)1 (1)2 (3)1 (1)2 (9)0 (0)3 (10)
Negative strainsd in PCR for stxb2 (1)1 (1)1 (2)1 (1)1 (5)0 (0)2 (7)
  • a P < 0.001 compared with that for non-O157.

  • b PCR-RFLP for stx according to Bastian et al. (1) and Lin et al. (27).

  • c Repeatedly weak results.

  • d Repeatedly negative results.