Serotype | Toxin phenotype | No. of isolates/total no. with indicated phenotype (%) |
---|---|---|

O1 | ExoU^{−} | 13/78 (16.7)^{a} |

ExoU^{+} | 0/21 (0.0) | |

O11 | ExoU^{+} | 7/21 (33.3)^{b} |

ExoU^{−} | 2/78 (2.6) | |

ExoS^{+}, T^{+}, or U^{+} | 8/50 (16.0)^{c} | |

ExoS^{−}T^{−}U^{−} | 1/49 (2.0) | |

O^{−} | ExoT^{−} | 29/64 (43.5)^{d} |

ExoT^{+} | 8/35 (22.9) | |

ExoU^{−} | 33/78 (42.3)^{e} | |

ExoU^{+} | 4/21 (19.0) | |

ExoS^{−}T^{−}U^{−} | 24/49 (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 ExoS^{−}T^{−}U^{−},*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 ExoS^{−}T^{−}U^{−}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]).