Shiga Toxins : A Review of Structure, Mechanism, and Detection

This book presents an overview of Shiga toxin-producing E. coli (STEC), with in-depth coverage of key areas such as recent Shiga toxin-related poisonings in Europe and the US, the structure, production, and mechanism of action of Shiga toxin, and current methods of detection. The globalization of food production has introduced new risk factors and intensified existing hazards, complicating the assurance of food safety. Foodborne illness outbreaks, such as those related to STEC, are becoming more common and more dangerous. The threat that these bacterial toxins pose to the food supply is magnified by the frequent occurrence and severity of Shiga toxin-caused disease. As a result, STEC and their toxins remain a primary concern in food safety. This review serves as a key resource for scientists in the field and public health and regulatory officials charged with maintaining food safety. This book also looks to the future of treatment of Shiga toxin-associated disease, specifically the translation of lab bench science into clinical therapeutic strategies. Dedication 6 Foreword 7 Acknowledgements 8 Contents 9 Abbreviations 11 About the Authors 15 Chapter 1: Introduction 17 References 20 Chapter 2: Outbreaks of Shiga Toxin-Related Poisoning 21 2.1 Human and Economic Impacts of STEC Outbreaks 21 2.2 Effectiveness of STEC in Causing Severe Disease Outbreaks 24 2.3 History of STEC Outbreaks and Their Continuing Evolution 24 2.4 Less Common Sources of STEC Outbreaks 28 References 30 Chapter 3: Structure of Shiga Toxins and Other AB5 Toxins 36 3.1 Structure of Shiga Toxins 36 3.2 Production, Activity, and Gene Structure 39 3.3 Binding to Sugars of Gangliosides 43 3.4 Entry to Cells and Intracellular Trafficking 45 3.5 Toxicity Differences Among Shiga Toxin Types and Subtypes 48 3.6 Other AB5 Protein Toxins 50 References 53 Chapter 4: Regulation of Shiga Toxin Production 61 4.1 Lambdoid Phages 61 4.2 Mobile Genetic Elements in E. coli: Transposons and Integrons 64 4.3 Phage Control of Shiga Toxin Production 65 4.4 Impacts of Phages and Mobile Elements on Pathogenicity 69 References 72 Chapter 5: Significant Threats to Human Health 76 5.1 Diverse Health Threats: Bacterial Species and Toxin Types, Subtypes, and Variants 76 5.2 Other Virulence Factors 78 5.3 Shiga Toxin Binding Sites: Host Cell Gangliosides 79 5.4 Development of Serious Sequelae of STEC Infection 80 5.5 Antibiotics in Treatment of Shiga Toxin-Associated Disease 81 5.6 Variations in Disease Associated with Stx Type and Subtype 82 5.7 Inferences from PCR Data 83 References 85 Chapter 6: Detection Methods for Shiga Toxins and Shiga Toxin-Producing E. coli 89 6.1 The Context and the Use of Culture Methods, Nucleic Acid Methods, and Immunoassays for STEC 89 6.2 Detection of Shiga Toxins by Bioassay: Animals, Cells, and Receptors 93 6.3 Structure-Based Assays for Stx: General Considerations and ELISAs Using Polyclonal Antibodies 95 6.4 Monoclonal Antibodies for Stx Detection, Inactivation, and Protection 98 6.5 Monoclonal Antibodies for Differentiating Stx Subtypes 99 6.6 Special-Purpose Immunoassay Methods: Amplification, Portability, and Arrays 100 6.7 Mass Spectrometric Methods for Detecting Shiga Toxins 103 References 106 Chapter 7: Conclusions and a Glimpse into the Future 113 7.1 Exploiting Shiga Toxins for Beneficial Uses 113 7.2 Future Strategies to Treat and Prevent Shiga Toxin-­Related Disease 114 7.3 Conclusions 119 References 121 Index 126 Front Matter....Pages i-xviii Introduction....Pages 1-4 Outbreaks of Shiga Toxin-Related Poisoning....Pages 5-19 Structure of Shiga Toxins and Other AB5 Toxins....Pages 21-45 Regulation of Shiga Toxin Production....Pages 47-61 Significant Threats to Human Health....Pages 63-75 Detection Methods for Shiga Toxins and Shiga Toxin-Producing E. coli ....Pages 77-100 Conclusions and a Glimpse into the Future....Pages 101-113 Back Matter....Pages 115-118