Genetic profiles of Shiga toxin and intimin genes found in stool broth cultures: a 2-year reference laboratory study

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• 作者：Pierre A. Michel ; Julie A. Kase
• 关键词：STEC ; Molecular detection ; Stx1 ; Stx2 ; Intimin
• 刊名：Diagnostic Microbiology and Infectious Disease
• 出版年：2009
• 出版时间：October 2009
• 年：2009
• 卷：65
• 期：2
• 页码：85-92
• 全文大小：202 K

文摘

Shiga toxin (Stx)-producing Escherichia coli (STEC) are associated with potentially serious illness in humans. STEC detection is often based on the presence of Stxs, Stx₁ and/or Stx₂, and intimin, encoded by the eae gene. A 2-year collection of stool broth cultures was tested for variants of stx₁, stx₂, and eae. Approximately 80 % (138 of 174) were positive for stx₁ and/or stx₂, with stx₁ as the most prevalent (66 % ). Of the stx₁ variants, stx₁ was the most common (76 % ) followed by stx_1c (22 % ). Analysis of stx₂-positive isolates found 20 (53 % ) stx₂, 13 (34 % ) stx₂/stx_2v-ha, 3 (8 % ) stx_2v-ha, 1 (3 % ) stx_2v-hb, and 1 (3 % ) stx_{2d-activatable}. Findings of stx₂/stx_2v-ha and stx_{2d-activatable} are noteworthy given associations with hemolytic uremic syndrome and increased cytotoxicity, respectively. Of the Stx positive, 94 (68 % ) were eae positive with 31 (33 % ) eae₁, 19 (20 % ) eae_γ1, and 18 (19 % ) eae_β1. A predominance of eae₁ may suggest a new pathogenic significance because, reportedly, eae_β1 is one of the most widespread variants.