Reissbrodt Rolf, Hammes Walter P, dal Bello Fabio, Prager Rita, Fruth Angelika, Hantke Klaus, Rakin Alexander, Starcic-Erjavec Marjanca, Williams Peter H
Robert Koch Institut, Wernigerode Branch, Wernigerode, Germany.
FEMS Microbiol Lett. 2009 Jan;290(1):62-9. doi: 10.1111/j.1574-6968.2008.01405.x. Epub 2008 Nov 10.
During routine quality control testing of diagnostic methods for Shiga toxin-producing Escherichia coli (STEC) using stool samples spiked with STEC, it was observed that the Shiga toxin could not be detected in 32 out of 82 samples tested. Strains of E. coli isolated from such stool samples were shown to be responsible for this inhibition. One particular isolate, named E. coli 1307, was intensively studied because of its highly effective inhibitory effect; this strain significantly reduced growth and Shiga toxin levels in coculture of several STEC strains regardless of serovar or Shiga toxin type. The probiotic E. coli Nissle 1917 inhibited growth and reduced Shiga toxin levels in STEC cultures to an extent similar to E. coli 1307, but commensal E. coli strains and several other known probiotic bacteria (enterococci, Bacillus sp., Lactobacillus acidophilus) showed no, or only small, inhibitory effects. Escherichia coli 1307 lacks obvious fitness factors, such as aerobactin, yersiniabactin, microcins and a polysaccharide capsule, that are considered to promote the growth of pathogenic bacteria. We therefore propose strain E. coli 1307 as a candidate probiotic for use in the prevention and treatment of infections caused by STEC.
在使用添加了产志贺毒素大肠杆菌（STEC）的粪便样本对STEC诊断方法进行常规质量控制检测期间，观察到在82个检测样本中有32个样本未检测到志贺毒素。从这类粪便样本中分离出的大肠杆菌菌株被证明是造成这种抑制作用的原因。其中一个名为大肠杆菌1307的特定分离株因其高效的抑制作用而受到深入研究；无论血清型或志贺毒素类型如何，该菌株在几种STEC菌株的共培养中均能显著降低生长和志贺毒素水平。益生菌大肠杆菌Nissle 1917对STEC培养物生长的抑制作用以及对志贺毒素水平的降低程度与大肠杆菌1307相似，但共生大肠杆菌菌株和其他几种已知的益生菌（肠球菌、芽孢杆菌属、嗜酸乳杆菌）则没有抑制作用，或只有很小的抑制作用。大肠杆菌1307缺乏明显的适应性因子，如气杆菌素、耶尔森菌素、微菌素和多糖荚膜，而这些因子被认为可促进病原菌的生长。因此，我们提议将大肠杆菌1307菌株作为预防和治疗STEC感染的候选益生菌。
