Preface ....................................................... vii
1 Introduction to Foodborne Pathogens .......................... 1
Introduction ................................................. 1
What is a Pathogen? .......................................... 4
What are the Attributes of Pathogenicity? .................... 4
Sources of Foodborne Pathogens ............................... 6
Meats, Ground Meat, and Organ Meats ....................... 6
Vacuum Packaged Meats ..................................... 7
Poultry ................................................... 7
Seafoods .................................................. 7
Fruits and Vegetables ..................................... 8
Dairy Products ............................................ 8
Delicatessen Foods ........................................ 9
Foodborne Pathogen Statistics and Socioeconomic Impact ....... 9
Why High Incidence of Foodborne Outbreaks? .................. 11
Surveillance and Reporting ............................... 12
Changes in the Agricultural Practices and the Food
Manufacturing ............................................ 12
Changes in Consumer Habits ............................... 14
Increased At-Risk Populations ............................ 14
Improved Detection Methods and Tracking of Pathogens ..... 14
Emerging Pathogens with Improved Survivability
in Stressed Conditions ................................... 15
Summary ..................................................... 15
Further Readings ............................................ 16
2 Biology of Microbes Associated with Food .................... 17
Introduction ................................................ 17
Bacteria .................................................... 17
Gram-Positive В acteria ..................................... 19
Cell Wall and Peptidoglycan .............................. 19
Teichoic Acid and Lipoteichoic Acid ...................... 21
Cytoplasmic Membrane ..................................... 21
Gram-Negative Bacteria ...................................... 21
Outer Membrane ........................................... 21
Peptidoglycan ............................................ 22
Periplasmic Space ........................................ 23
Protein Secretion Systems ................................ 23
Accessory Structures in Gram-Positive and Gram-Negative
Bacteria ................................................. 23
Endospore Formation ...................................... 24
Diseases Caused by Viruses .................................. 26
Introduction ............................................. 26
Significance of Viral Infection .......................... 28
Sources and Transmission ................................. 28
Virus Classification/Taxonomy ............................ 28
Structure ................................................ 28
Adenovirus ............................................... 29
Astrovirus ............................................... 29
Rotavirus ................................................ 29
Polio .................................................... 30
Hepatitis A Virus ........................................ 30
Norovirus ................................................ 32
Bird-Flu Virus ........................................... 33
Bovine Spongiform Encephalopathy ......................... 35
Prevention and Control of Foodborne Viruses .............. 36
Diseases Caused by Parasites ................................ 37
Characteristics .......................................... 37
Protozoa ................................................. 37
Flat Worm (Tapeworm) ..................................... 41
Roundworm ................................................ 42
Diseases Caused by Mycotoxins ............................ 42
Characteristics .......................................... 42
Aflatoxin ................................................ 44
Ochratoxin ............................................... 45
Fumonosins ............................................... 45
Tricothecenes ............................................ 45
Patulin .................................................. 46
Penicillic Acid .......................................... 46
Zearalenone .............................................. 46
Citrinin ................................................. 46
Alternaria Toxin ......................................... 46
Ergot Alkaloids .......................................... 46
Prevention and Control of Mycotoxins ........................ 47
Diseases Caused by Seafood Toxins ........................... 47
Ciguatera Toxin .......................................... 47
Scombroid Toxin .......................................... 47
Saxitoxin ................................................ 48
Summary ..................................................... 48
Further Readings ......................................... 49
3 Host Defense Against Foodborne Pathogens .................... 51
Introduction ................................................ 51
Innate Immune Response ...................................... 51
Adaptive Immune Response .................................... 52
Innate Immunity of Intestinal Tract ......................... 53
Skin ........................................................ 53
Mucus Membrane ........................................... 53
Goblet Cells and Mucus ................................... 54
Antimicrobial Peptides ................................... 55
Resident Microbiota ...................................... 56
Toll-Like Receptors ...................................... 58
Other Components of Innate Immunity ...................... 59
Adaptive Immunity ........................................... 60
Characteristics of Adaptive Immune Response ...............60
Phases of Immune Response ................................ 61
Tissues and Cells of Immune System .......................... 61
Tissues .................................................. 61
Cells of Immune System ................................... 63
Cytokines ................................................... 68
Cytokines in Natural Immunity ............................ 70
B-Lymphocytes ............................................ 71
Classes of Immunoglobulins ............................... 73
Diversity of Antibodies .................................. 73
Antibody Production ...................................... 74
Function of Antibody ..................................... 75
Antigen ..................................................... 76
Types of Antigens ........................................ 76
Epitope or Antigenic Determinant ......................... 76
Hapten ................................................... 77
Antigen-Antibody Reaction ................................ 77
The Major Histocompatibility Complex ........................ 77
Structure of MHC ......................................... 77
Antigen Presenting Cells ................................. 78
МНС-Restricted Antigen Processing and Presentation ....... 80
The Complement System ....................................... 81
The Classical Pathway .................................... 81
Alternative Pathway ...................................... 83
Function of Complement ................................... 84
Control of Complement Activation ......................... 84
Immunity to Microbes ........................................ 85
Extracellular Bacteria ................................... 85
Innate Immunity .......................................... 86
Adaptive Immune Response ................................. 86
Evasion of Immune System by Extracellular Bacteria ....... 86
Intracellular Bacteria ...................................... 87
Innate Immunity .......................................... 87
Adaptive Immunity ........................................ 87
Evasion of Immune System ................................. 88
Immunity to Virus ........................................... 88
Innate Immunity .......................................... 88
Adaptive Immunity ........................................ 89
Evasion of Immune System by Viruses ...................... 89
Immunity to Parasites ....................................... 89
Innate Immunity .......................................... 90
Adaptive Immunity ........................................ 90
Evasion of Immune System ................................. 90
Summary ..................................................... 90
Further Readings ......................................... 91
4 General Mechanism of Pathogenesis for Foodborne
Pathogens ................................................... 93
Introduction ................................................ 93
Foodborne Infection ......................................... 93
Infectious Dose .......................................... 94
Colonization and Adhesion Factors ........................ 94
Invasion and Intracellular Residence ..................... 97
Iron Acquisition ........................................ 100
Motility and Chemotaxis ................................. 100
Evasion of Immune System ................................ 100
Intoxication ............................................... 101
Toxicoinfection ............................................ 101
Toxins .................................................. 101
Endotoxin ............................................... 106
Genetic Regulation and Secretion Systems for Virulence
Factors .................................................... 108
Pathogenicity Islands ................................... 108
Protein Secretion System ................................ 108
Regulation of Virulence Genes ........................... 110
Summary .................................................... 111
Further Readings ........................................ 111
5 Animal and Cell Culture Models to Study Foodborne
Pathogen Interaction ....................................... 113
Introduction ............................................... 113
Animal Model ............................................... 113
Organ Culture .............................................. 114
Ligated-Ileal Loop Assay ................................ 115
Embryonated-Egg Assay ................................... 115
Cultured Cell Lines ........................................ 115
Measurement of Virulence ................................... 118
Animal Model ............................................ 118
Cell Culture Model ...................................... 118
Measurement of Specific Steps in Colonization and
Invasion ................................................... 121
Animal Model ............................................ 121
Cell Culture Models ..................................... 122
Summary .................................................... 122
Further Readings ........................................ 123
6 Staphylococcus aureus ...................................... 125
Introduction ............................................... 125
Classification ............................................. 125
Morphology ................................................. 126
Cultural and Biochemical Characteristics ................... 126
Virulence Factors .......................................... 127
Food Association and Toxin Production ...................... 128
Enterotoxins ............................................... 128
Molecular Regulation of Virulence Gene Expression .......... 129
Mechanism of Pathogenesis .................................. 130
Symptoms ................................................... 131
Prevention and Control ..................................... 132
Detection .................................................. 132
Culture Methods ......................................... 132
Cytotoxicity-Based Assays ............................... 132
Nucleic Acid-Based Methods .............................. 132
Immunoassays ............................................ 133
Other Rapid Methods ..................................... 133
Summary .................................................... 133
Further Readings ........................................ 134
7 Bacillus cereus and Bacillus anthracis ..................... 135
Introduction ............................................... 135
Biology .................................................... 135
Classification ............................................. 136
Foods Involved ............................................. 137
Toxins and Enzymes ......................................... 137
Emetic Toxin ............................................ 138
Enterotoxins ............................................ 139
Hemolysins .............................................. 140
Regulation of Toxins ....................................... 140
Pathogenesis ............................................... 140
Emetic Toxin ............................................ 141
Diarrheagenic Toxin ..................................... 141
Prevention and Control ..................................... 141
Detection .................................................. 142
Conventional Methods .................................... 142
Animal and Cell Culture Method .......................... 143
PCR ..................................................... 143
Antibody-Based Assay .................................... 144
Bacillus anthracis ......................................... 144
Biology ................................................. 144
Virulence Factors ....................................... 144
Pathogenesis ............................................ 146
Treatment and Prevention ................................ 146
Detection of B. anthracis ............................... 146
Summary .................................................... 147
Further Readings ........................................ 147
8 Clostridium botulinum and Clostridium perfringens .......... 149
Introduction ............................................... 149
Classification of Clostridium Species ...................... 149
Clostridium botulinum ...................................... 149
Biology ................................................. 149
Sources ................................................. 150
Botulism ................................................ 151
Mechanism of Pathogenesis ............................... 153
Symptoms ................................................ 156
Prevention and Treatment ................................ 156
Detection ............................................... 157
Clostridium perfringens .................................... 158
Biology ................................................. 158
Sources ................................................. 158
Toxins .................................................. 158
Genetic Regulation of Virulence ......................... 160
Pathogenic Mechanism .................................... 160
Symptoms, Prevention, and Control ....................... 162
Detection ............................................... 162
Summary .................................................... 162
Further Readings ........................................ 163
9 Listeria monocytogenes ..................................... 165
Introduction ............................................... 165
Classification ............................................. 166
Biology .................................................... 166
Flagella ................................................... 167
Sources .................................................... 168
Disease .................................................... 168
Gastrointestinal Form ................................... 168
Systemic Listeriosis .................................... 169
Abortion and Neonatal Listeriosis ....................... 169
Mechanism of Pathogenesis .................................. 170
Intestinal Phase of Infection and Systemic Spread .......... 170
Attachment and Entry ....................................... 171
Internalin A ............................................ 173
Internalin В ............................................ 175
LAP ..................................................... 176
Autolysin Amidase ....................................... 176
p60 ..................................................... 176
Vip ..................................................... 177
Miscellaneous Adhesion Proteins ............................ 177
Lysis of Vacuole (Phagosome) ............................... 177
Listeriolysin ........................................... 177
Phosphatidylinositol-Specific PLC ....................... 178
Intracellular Growth ....................................... 178
Cell-to-Cell Spread ........................................ 178
ActA .................................................... 178
Phosphatidylcholine-Specific PLC ........................ 179
Regulation of Virulence Genes .............................. 179
Immunity to Listeria monocytogenes ......................... 180
ftevention and Control ..................................... 180
Summary .................................................... 181
Further Readings ........................................ 182
10 Escherichia coli ........................................... 183
Introduction ............................................... 183
Sources .................................................... 183
Classification ............................................. 184
Serotypes ............................................... 184
Virotypes ............................................... 184
Enterotoxigenic E. coli .................................... 185
Virulence Factors and Pathogenesis ...................... 186
Enteropathogenic E. coli ................................... 188
Pathogenesis of EPEC .................................... 188
LEE and Regulation of Virulence Genes ................... 190
Enterohemorrhagic E. coli .................................. 190
Biology ................................................. 190
Food Association ........................................ 191
ЕНЕС Pathogenesis ....................................... 191
Type III Secretion System and Delivery of Effector
Proteins During ЕНЕС Pathogenesis ....................... 193
Inflammation ............................................ 195
Enterohemolysin ......................................... 195
Other Virulence Factors ................................. 195
Regulation of Virulence Genes ........................... 196
Symptoms and Complications .............................. 196
Enteroaggregative E. coli .................................. 196
Characteristics ......................................... 196
Adhesion Factors ........................................ 196
Toxins .................................................. 197
EAEC Pathogenesis ....................................... 197
Symptoms and Diagnosis .................................. 197
Enteroinvasive E. coli ..................................... 197
Characteristics ......................................... 197
Disease and Symptoms .................................... 197
Diffusely Adhering E. coli ................................. 198
Animal and Cell Culture Model Used for Diagnosis of
E. coli ................................................. 198
Control and Prevention of E. со/г-Mediated Diarrhea ..... 198
Summary .................................................... 199
Further Readings ........................................ 200
11 Salmonella enterica ........................................ 201
Introduction ............................................... 201
Biology .................................................... 201
Source and Transmission .................................... 202
Classification ............................................. 202
Major Groups ............................................... 203
Pathogenic Mechanism ....................................... 203
Gastroenteritis ............................................ 203
Pathogenicity Islands ...................................... 205
SPI-1 ................................................... 205
SPI-2 ................................................... 206
SPI-3 ................................................... 206
SPI-4 ................................................... 206
SPI-5 ................................................... 206
SPI-6 ................................................... 206
SPI-7 or Major Pathogenicity Island (MPI) ............... 206
SPI-8 ................................................... 206
SPI-9 ................................................... 207
SPI-10 .................................................. 207
Salmonella Genomic Island-1 (SGI-1) ..................... 207
High Pathogenicity Island (HPI) ......................... 207
Type III Secretion System .................................. 207
Adhesion and Colonization .................................. 207
Invasion and Intracellular Growth .......................... 208
Phagocytosis by M-Cells ................................. 208
Phagocytosis by Dendritic Cells ......................... 208
Induced Phagocytosis .................................... 209
Survival in Phagocytes .................................. 211
Regulation of Virulence Genes .............................. 211
RpoS Regulator .......................................... 211
ATR Response ............................................ 212
Treatment and Prevention of Gastroenteritis ................ 212
Typhoid Fever .............................................. 212
Detection ............................................... 214
Summary .................................................... 214
Further Readings ........................................ 215
12 Campylobacter and Arcobacter ............................... 217
Campylobacter .............................................. 217
Introduction ............................................ 217
Biology ................................................. 218
Classification .......................................... 219
Sources ................................................. 219
Antibiotic Resistance ................................... 219
Disease ................................................. 220
Mechanism of Pathogenesis ............................... 220
Regulation of Virulence Genes ........................... 222
Symptoms ................................................ 222
Arcobacter ................................................. 222
Prevention and Control .................................. 223
Detection of Campylobacter and Arcobacter ............... 224
Summary .................................................... 224
Further Readings ........................................ 225
13 Yersinia enterocolitica and Yersinia pestis ................ 227
duction .................................................... 227
Yersinia enterocolitica .................................... 228
Biology ................................................. 228
Classification .......................................... 228
Sources ................................................. 228
Virulence Factors ....................................... 229
Chromosome-Linked Virulence Gene Products ............... 229
Plasmid (pVY)-Linked Virulence Gene Products ............ 231
Type III Secretion System ............................... 232
Pathogenic Mechanism .................................... 232
Symptoms ................................................ 234
Prevention and Control .................................. 235
Detection ............................................... 235
Yersinia pestis ............................................ 236
Introduction ............................................ 236
Biology ................................................. 237
Pathogenesis ............................................ 237
Treatment and Prevention ................................ 238
Detection of Y. pestis .................................. 238
Summary .................................................... 238
Further Readings ........................................ 239
14 Vibrio cholerae, V. parahaemolyticus, V. vulnificus ........ 241
Introduction ............................................... 241
Classification ............................................. 241
Biology .................................................... 241
Source and Transmission .................................... 242
Vibrio cholerae ............................................ 242
Introduction ............................................ 242
Biology ................................................. 242
Gastroenteritis ......................................... 243
Pathogenic Mechanism .................................... 244
Cholera Toxin ........................................... 244
Other Toxins ............................................ 245
Immune Response to CT ................................... 246
Vibrio parahaemolyticus .................................... 246
Biology ................................................. 246
Pathogenesis ............................................ 247
Toxins .................................................. 247
Vibrio vulnificus .......................................... 248
Introduction ............................................ 248
Pathogenic Mechanism .................................... 248
Acquisition of Iron ..................................... 248
Flagella and Motility ................................... 249
Hemolysin ............................................... 249
Metalloprotease ......................................... 249
Septicemia .............................................. 249
Wound Infection ......................................... 250
Control and Prevention of Infection by Vibrio species ... 250
Detection of Vibrio species ..............................251
Summary .................................................... 251
Further Readings ........................................ 252
15 Shigella species ........................................... 253
Introduction ............................................... 253
Biology .................................................... 253
Classification ............................................. 254
Source and Transmission .................................... 254
Pathogenesis ............................................... 254
Invasion ................................................... 256
Intracellular Multiplication ............................... 259
Bacterial Movement: Inter- and Intracellular Spreading ..... 259
Cell Death and Inflammation ................................ 260
Shiga Toxin and Hemolytic Uremic Syndrome .................. 260
Regulation of Virulence Genes .............................. 261
Resistance Against Infection ............................... 261
Symptoms ................................................... 262
Prevention and Control ..................................... 262
Diagnosis and Detection .................................... 263
Animal and Cell Culture Models .......................... 263
Bacterial Culture Methods ............................... 263
Immunological Methods ................................... 263
Molecular Techniques .................................... 264
Summary .................................................... 264
Further Readings ........................................ 264
Glossary ...................................................... 267
Index ......................................................... 269
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