Greco Karla M, McDonough Marie A, Butterton Joan R
Infectious Disease Division, Massachusetts General Hospital, Boston, Massachusetts, USA.
J Infect Dis. 2004 Jul 15;190(2):330-4. doi: 10.1086/421706. Epub 2004 Jun 9.
The Shiga toxin (Stx) region of Shigella dysenteriae 1 lies on a defective prophage homologous to lambdoid bacteriophages in Stx-producing Escherichia coli. S. dysenteriae 1 strains obtained in locations throughout the world over the course of the past 60 years were assessed for variations in the Stx region by use of polymerase chain reaction and sequence analysis. The defective prophage was present in all strains examined, suggesting that all S. dysenteriae 1 isolates derive from a clone that resulted from a single phage-integration event. All western-hemisphere strains have an additional iso-IS1 insertion element upstream of stxAB, implying that there has been minimal exchange of strains between hemispheres in recent decades.
痢疾志贺氏菌1型的志贺毒素（Stx）区域位于一个缺陷前噬菌体上，该前噬菌体与产志贺毒素大肠杆菌中的λ样噬菌体同源。通过聚合酶链反应和序列分析，对过去60年中在世界各地获得的痢疾志贺氏菌1型菌株的Stx区域变异情况进行了评估。在所检测的所有菌株中均存在缺陷前噬菌体，这表明所有痢疾志贺氏菌1型分离株均源自一次单一噬菌体整合事件产生的克隆。所有西半球菌株在stxAB上游还有一个额外的iso-IS1插入元件，这意味着近几十年来半球间菌株的交换极少。
