E. coli (eBook)

Front Cover 1
Escherichia coli: Virulence Mechanisms of a Versatile Pathogen 4
Copyright Page 5
Contents 8
Contributors 18
Introduction 22
Part I: Escherichia coli The Organism 28
Chapter 1. The Genomes of Escherichia coli K-12 and Pathogenic E. coli 30
Introduction 30
History of E. coli Genomics 31
Analysis and Comparison of E. coli Genomes 34
Functional Analyses of E. coli Genes 64
The Future of E. coli Genomics 70
Acknowledgments 71
References 71
Chapter 2. Evolution of Pathogenic Escherichia coli 82
Introduction 82
Evolution in E. coli 83
Virulence Factors and Virulence 84
Phylogenetic Relationships in E. coli 85
Evolution of Individual VFs 85
Diversifying and Directional Selection 86
Phylogenetic Distribution of VFs 88
Pathogenicity-Associated Islands 89
Virulence Plasmids 90
Repeated Emergence of Virulent Clones 91
Genomic Background and Virulence 91
Phylogenetic Distribution of Pathogenic E. coli 92
Intestinal Pathogenic E. coli 93
Why Pathogenic E. coli? 95
Summary 97
Acknowledgments 97
References 97
Part II: Escherichia coli Pathotypes 10
Chapter 3. Enteropathogenic Escherichia coli 108
Characteristics of EPEC and EPEC Infections 108
EPEC Molecular Pathogenesis 110
Integration of EPEC Pathogenic Features 126
Diagnosis, Prevention, and Control of EPEC Infections 128
References 131
Chapter 4. Enterohemorrhagic and Other Shiga Toxin–Producing Escherichia coli 146
Background 146
Epidemiology of STEC 149
Clinical Manifestations of STEC Infection 152
Shiga Toxins 153
Molecular Pathogenesis 157
HUS Pathogenesis and Effects of Shiga Toxin on Various 162
Prospects for Prevention and Control 168
References 169
Chapter 5. Enterotoxigenic Escherichia coli 182
ETEC Epidemiology 183
ETEC Pathogenesis 184
ETEC Virulence Factors 184
Treatment and Prevention of ETEC Infections 197
References 200
Chapter 6. Enteroaggregative and Diffusely Adherent Escherichia coli 216
Enteroaggregative E. coli 216
Diffusely Adhering E. coli 227
References 230
Chapter 7. Shigella and Enteroinvasive Escherichia coli: Paradigms for Pathogen Evolution and Host-Parasite Interactions 236
Introduction 236
Classification and Biochemical Characteristics 237
Characteristics of Disease 238
Virulence Factors and Genetics 243
Evolution of Shigella Species and EIEC 256
Conclusions 258
Acknowledgments 258
References 258
Chapter 8. Uropathogenic Escherichia coli 266
Epidemiology and Clinical Symptoms 266
UPEC as a Defined Group of Strains 267
Virulence Factors 270
Model 285
Summary 286
References 286
Chapter 9. Meningitis-Associated Escherichia coli 296
Introduction 296
Models of Blood-Brain Barrier 297
A Threshold Level of Bacteremia 297
Bacterial Structures Contributing to Binding to BMECs 298
Bacterial Structures Contributing to Invasion of BMECs 298
E. coli K1 Genome 303
Bacterial Trafficking of BMEC 303
Traversal of the Blood-Brain Barrier as Live Bacteria 309
Conclusion 309
Acknowledgments 310
References 311
Part III: Escherichia coli Virulence Factors 13
Chapter 10. Adhesive Pili of the Chaperone-Usher Family 316
Introduction 316
Characteristics of Pili 318
Biogenesis of Pili 324
Conclusion 329
Acknowledgments 330
References 330
Chapter 11. Type IV Pili 334
Introduction 334
Distribution 337
Genetic Organization 338
Role in Virulence 339
Pilus Structure 340
Proteins Involved in Pilus Biogenesis and Function 342
Regulation of BFP Expression 354
Acknowledgments 355
References 355
Chapter 12. The LEE-Encoded Type III Secretion System in EPEC and EHEC: Assembly, Function, and Regulation 364
Introduction 364
Secretion Strategies in Gram-Negative Bacteria 365
General Features of Type III Secretion 366
Type III Secretion in EPEC and EHEC 369
Regulation of LEE Gene Expression 373
Conclusions 380
References 380
Chapter 13. Hemolysin 388
Introduction 388
Synthesis of E. coli Prohemolysin 392
Toxin Maturation 394
Secretion of Hemolysin 397
Acknowledgments 401
References 402
Chapter 14. Capsule and Lipopolysaccharide 406
Introduction 406
Clinical Classification of E. coli 407
Physical and Genetic Characteristics of Capsule and LPS 408
Evolutionary Roots of Capsule and O-Specific Antigen Gene Clusters 413
The Role of Capsule and LPS in the Pathogenesis of Infection 414
Surface Polysaccharides Stimulate and Attenuate the Host Infiammatory Response 421
Capsule and O-Antigen May Subvert the Host’s Acquired Immunologic Response 423
Summary 424
References 424
Index 432
Color Plate Section 446