Schmidt H
Institut für Hygiene und Mikrobiologie der Universität Würzburg, Germany.
Res Microbiol. 2001 Oct;152(8):687-95. doi: 10.1016/s0923-2508(01)01249-9.
Shiga toxins (Stx) comprise a family of potent cytotoxins that are involved in severe human disease. Stx are mainly produced by Escherichia coli isolated from human and nonhuman sources, and by Shigella dysenteriae type 1. The genes encoding Stx are thought to be generally encoded in the genome of lambdoid prophages (Stx-converting bacteriophages; Stx phages). They share a unique position in the late region of the phage genome downstream of the late promoter PR'. This location suggests that expression of stx is controlled by a Q-like antiterminator. Therefore, induction of Stx-converting prophages appears to trigger increased production of Stx. Following induction, Stx phages can be transduced in vivo and in vitro into other bacteria. Stx phages play an important role in the expression of Stx and in lateral gene transfer and are therefore a contribution to the emergence of new Stx-producing E. coli (STEC) variants.
志贺毒素（Stx）是一类强效细胞毒素，与严重的人类疾病有关。Stx主要由从人类和非人类来源分离出的大肠杆菌以及痢疾志贺菌1型产生。编码Stx的基因通常被认为是由λ样原噬菌体（Stx转换噬菌体；Stx噬菌体）的基因组编码的。它们在噬菌体基因组晚期区域的晚期启动子PR'下游占据独特位置。这一位置表明stx的表达受一种类似Q的抗终止子控制。因此，Stx转换原噬菌体的诱导似乎会引发Stx产量的增加。诱导后，Stx噬菌体可在体内和体外转导至其他细菌。Stx噬菌体在Stx的表达以及横向基因转移中发挥重要作用，因此对新的产Stx大肠杆菌（STEC）变体的出现有一定作用。
