TABLE 4.

Associations between O-antigen serotypes and TTS toxin phenotypes

SerotypeToxin phenotypeNo. of isolates/total no. with indicated phenotype (%)
O1ExoU13/78 (16.7)a
ExoU+0/21 (0.0)
O11ExoU+7/21 (33.3)b
ExoU2/78 (2.6)
ExoS+, T+, or U+8/50 (16.0)c
ExoSTU1/49 (2.0)
OExoT29/64 (43.5)d
ExoT+8/35 (22.9)
ExoU33/78 (42.3)e
ExoU+4/21 (19.0)
ExoSTU24/49 (49.0)f
ExoS+, T+, or U+13/50 (26.0)
  • a For comparison of prevalences between ExoU and ExoU+, P = 0.04 by Fisher's exact test (relative risk, 1.3 [95% confidence interval, 1.2 to 1.5]).

  • b For comparison of prevalences between ExoU+ and ExoU, P = 0.0002 by Fisher's exact test (relative risk, 5.0 [95% confidence interval, 2.8 to 9.1]).

  • c For comparison of prevalences between ExoS+, T+, or U+ and ExoSTU, P = 0.02 by Fisher's exact test (relative risk, 1.9 [95% confidence interval, 1.4 to 2.6]).

  • d For comparison of prevalences between ExoT and ExoT+, P = 0.02 by Fisher's exact test (relative risk, 1.4 [95% confidence interval, 1.1 to 1.8]).

  • e For comparison of prevalences between ExoU and ExoU+, P = 0.04 by Fisher's exact test (relative risk, 1.2 [95% confidence interval, 1.0 to 1.5]).

  • f For comparison of prevalences between ExoSTU and ExoS+, T+, or U+, P = 0.02 by Fisher's exact test (relative risk, 1.6 [95% confidence interval, 1.1 to 2.4]).