Saeedi Pardis, Yazdanparast Maryam, Behzadi Elham, Salmanian Ali Hatef, Mousavi Seyed Latif, Nazarian Shahram, Amani Jafar
Applied Microbiology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.
Department of Biology, Faculty of Basic Sciences, Shahed University, Tehran, Iran.
Microb Pathog. 2017 Feb;103:186-195. doi: 10.1016/j.micpath.2017.01.001. Epub 2017 Jan 3.
Enterohemorrhagic Escherichia coli (EHEC) serotype O157:H7 is a food-borne pathogen that younger children are most prone to this microorganism. Hemolytic Uremic Syndrome (HUS) caused by EHEC, leads to the destruction of red blood cells and kidney failure. The virulence of E.coli O157:H7 is attributed to fimbriae, that facilitate colonization of bacteria within the colon and verotoxins (VT) or Shiga toxins (Stx) that are released into the blood. Although, in most cases, the infection is self-limitedin young children and aged population, it may cause HUS. Therefore, several investigations are performed in order to offer effective therapies and vaccines, which can prevent and treat the infection in appropriate time. As the pathogenesis of this infection is complicated, a multi-targeted strategy is required. Since cattle are the most important reservoir of EHEC and the root of contamination, reducing E. coli O157:H7 at the farm level should decrease the risk of human illness. Several vaccine approaches have been employed with different proper outcomes in animal models, including recombinant proteins (virulence factors such as; Stx1/2, intimin, EspA, fusion proteins of A and B Stx subunits), avirulent ghost cells of EHEC O157:H7, live attenuated bacteria expressing recombinant proteins, recombinant fimbrial proteins. In addition to protein-based vaccines, DNA vaccines have provided proper prevention in the laboratory animal model. This review paper summarizes the previous studies, current status and future perspective of different immunization strategies for eradicating Enterohemorrhagic Escherichia coli O157:H7.
肠出血性大肠杆菌（EHEC）O157:H7血清型是一种食源性病原体，幼儿最易感染这种微生物。由EHEC引起的溶血性尿毒症综合征（HUS）会导致红细胞破坏和肾衰竭。大肠杆菌O157:H7的毒力归因于菌毛，其有助于细菌在结肠内定植，以及释放到血液中的志贺毒素（VT）或志贺样毒素（Stx）。尽管在大多数情况下，幼儿和老年人群的感染是自限性的，但仍可能导致HUS。因此，人们进行了多项研究，以提供有效的治疗方法和疫苗，从而能够在适当的时候预防和治疗感染。由于这种感染的发病机制复杂，需要采取多靶点策略。由于牛是EHEC最重要的宿主和污染源，在农场层面减少大肠杆菌O157:H7应能降低人类患病风险。已经采用了几种疫苗方法，在动物模型中取得了不同程度的良好效果，包括重组蛋白（如毒力因子Stx1/2、紧密黏附素、EspA、A和B Stx亚基的融合蛋白）、EHEC O157:H7的无毒空壳菌、表达重组蛋白的减毒活细菌、重组菌毛蛋白。除了基于蛋白质的疫苗外，DNA疫苗在实验动物模型中也提供了有效的预防作用。本文综述总结了根除肠出血性大肠杆菌O157:H7的不同免疫策略的先前研究、现状和未来展望。
