Multicenter Evaluation of a Sequence-Based Protocol for Subtyping Shiga Toxins and Standardizing Stx Nomenclature

Author:

Scheutz Flemming1,Teel Louise D.2,Beutin Lothar3,Piérard Denis4,Buvens Glenn4,Karch Helge5,Mellmann Alexander5,Caprioli Alfredo6,Tozzoli Rosangela6,Morabito Stefano6,Strockbine Nancy A.7,Melton-Celsa Angela R.2,Sanchez Maria2,Persson Søren1,O'Brien Alison D.2

Affiliation:

1. WHO Collaborating Centre for Reference and Research on Escherichia and Klebsiella, Unit of Foodborne Bacteria and Typing, Department of Microbiology and Infection Control, Statens Serum Institut, Copenhagen, Denmark

2. Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA

3. National Reference Laboratory for Escherichia coli, Federal Institute for Risk Assessment (BfR), Berlin, Germany

4. National Reference Center for Shiga Toxin/Verotoxin Producing E. coli, Department of Microbiology, Universitair Ziekenhuis Brussel, Brussels, Belgium

5. Institute of Hygiene and National Consulting Laboratory for Hemolytic Uremic Syndrome, University of Münster, Münster, Germany

6. Istituto Superiore di Sanità, Rome, Italy

7. National Escherichia and Shigella Reference Unit, Enteric Diseases Laboratory Branch, National Center for Emerging and Zoonotic Infectious Diseases (CDC), Atlanta, Georgia, USA

Abstract

ABSTRACT When Shiga toxin-producing Escherichia coli (STEC) strains emerged as agents of human disease, two types of toxin were identified: Shiga toxin type 1 (Stx1) (almost identical to Shiga toxin produced by Shigella dysenteriae type 1) and the immunologically distinct type 2 (Stx2). Subsequently, numerous STEC strains have been characterized that express toxins with variations in amino acid sequence, some of which confer unique biological properties. These variants were grouped within the Stx1 or Stx2 type and often assigned names to indicate that they were not identical in sequence or phenotype to the main Stx1 or Stx2 type. A lack of specificity or consistency in toxin nomenclature has led to much confusion in the characterization of STEC strains. Because serious outcomes of infection have been attributed to certain Stx subtypes and less so with others, we sought to better define the toxin subtypes within the main Stx1 and Stx2 types. We compared the levels of relatedness of 285 valid sequence variants of Stx1 and Stx2 and identified common sequences characteristic of each of three Stx/Stx1 and seven Stx2 subtypes. A novel, simple PCR subtyping method was developed, independently tested on a battery of 48 prototypic STEC strains, and improved at six clinical and research centers to test the reproducibility, sensitivity, and specificity of the PCR. Using a consistent schema for nomenclature of the Stx toxins and stx genes by phylogenetic sequence-based relatedness of the holotoxin proteins, we developed a typing approach that should obviate the need to bioassay each newly described toxin and that predicts important biological characteristics.

Publisher

American Society for Microbiology

Subject

Microbiology (medical)

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3