Biomphalaria Snails and Larval Trematodes (eBook)

Preface 6
Contents 8
Contributors 10
Chapter 1: Biosystematics of Biomphalaria spp. with an Emphasis on Biomphalaria glabrata 12
1.1 Introduction 13
1.2 The Shell of Biomphalaria, a Tricky Tool for Identification 14
1.3 The Anatomy of Reproductive Tracts, a Reliable Tool for Identifying Biomphalaria Species 19
1.4 Molecular Phylogenetic and Phylogeographic Approaches 26
1.5 Reproductive Isolation 29
1.6 Biomphalaria Systematics and the Interaction with Schistosoma mansoni 34
1.7 Conclusions and Perspectives 36
References 38
Chapter 2: Laboratory Rearing of Biomphalaria glabrata Snails and Maintenance of Larval Schistosomes In Vivo and In Vitro 44
2.1 Introduction 44
2.2 Snail Rearing and Maintenance 45
2.2.1 Measures of Successful Snail Rearing 45
2.2.1.1 Survival and Longevity 46
2.2.1.2 Growth and Maturation 46
2.2.1.3 Fecundity 46
2.2.2 Physical and Biological Factors that Affect Rearing 46
2.2.2.1 Temperature 47
2.2.2.2 Diet 47
2.2.2.3 Crowding 48
2.2.2.4 Parasitism 48
Trematodes (Schistosomes and Other Trematodes) 49
Organisms Other than Trematodes 50
2.2.3 Methods of Snail Rearing 51
2.2.3.1 Axenic Snail Rearing 53
2.3 Methods of Infecting Snails 53
2.3.1 Miracidial Infection 53
2.3.2 Transplantation of Parthenitae 54
2.4 In Vitro Culture of Snail Tissues and Cells 57
2.5 Concluding Remarks 59
References 60
Chapter 3: Biomphalaria: Natural History, Ecology and Schistosome Transmission 67
3.1 Introduction 67
3.2 Environmental Factors Affecting Biomphalaria 68
3.2.1 Temperature and Light 68
3.2.2 Water Chemistry and Conductivity 70
3.2.3 Depth and Type of Water Body 72
3.2.4 Aquatic Plants 73
3.3 Effects of Water Development Projects on Biomphalaria 74
3.4 Role of Biomphalaria in Transmission of Schistosoma Mansoni 76
3.4.1 Species Specificity 76
3.4.2 Impact of Seasonality on Transmission 76
3.4.3 Focality of Transmission 78
3.5 Monitoring and Surveillance Systems 79
3.5.1 Use of Geographical Information System for Predicting Distribution of Snails and Disease 79
3.5.2 Molecular Markers for Identification of Prepatent Infections in Snails 80
3.6 Concluding Remarks 81
References 82
Chapter 4: Studies of Biomphalaria Snails Infected with Larval Trematodes Using Chromatography and Atomic Spectrometry 90
4.1 Introduction 90
4.2 Thin Layer Chromatography Principles and Methods 92
4.2.1 Principles 92
4.2.2 Snail Maintenance and Sample Preparation 92
4.2.3 Sample Extraction and Purification 93
4.2.4 Layers and Mobile Phases 94
4.2.5 Standard and Sample Solution Application 95
4.2.6 Plate Development with the Mobile Phase 95
4.2.7 Methods for Detection of Separated Zones 96
4.2.8 Documentation of Chromatograms 96
4.2.9 Identification of Zones 96
4.2.10 Quantification of Analytes 96
4.2.11 Statistical Analysis of Data 97
4.3 Thin Layer Chromatography Applications 97
4.3.1 Introduction to Thin Layer Chromatography Applications 97
4.3.2 Lipids in Biomphalaria Infected with Larval Trematodes 97
4.3.3 Effects of Diet and Larval Trematodes on Lipids in Biomphalaria Snails 99
4.3.4 Amino Acids in Biomphalaria Snails Infected with Larval Trematodes 101
4.3.5 Carbohydrates in Biomphalaria Snails Infected with Larval Trematodes 102
4.3.6 Lipophilic Pigments in Biomphalaria Snails Infected with Larval Trematodes 102
4.4 Gas Chromatography 103
4.4.1 Principles 103
4.4.2 Methods and Applications 103
4.5 Column High-Performance Liquid Chromatography 104
4.5.1 Principles 104
4.5.2 Methods and Applications 105
4.6 Inductively Coupled Plasma-Atomic Emission Spectrometry and Atomic Absorption Spectrometry 107
4.6.1 Principles 107
4.6.2 Methods and Applications 107
4.7 Concluding Remarks 108
References 109
Chapter 5: Effects of Larval Schistosomes on Biomphalaria Snails 112
5.1 Introduction 112
5.2 Survival and Mortality 113
5.2.1 Mortality 113
5.2.2 Miracidial Dose 114
5.2.3 Snail Age 114
5.2.4 Susceptibility 115
5.3 Growth and Metabolism 115
5.3.1 Growth 115
5.3.2 Snail Age 115
5.3.3 B. alexandrina and B. pfeifferi 116
5.3.4 Glucose and Glycolytic Enzymes 116
5.3.5 Glycogen 117
5.3.6 Maltose 118
5.3.7 Anaerobic Metabolism 118
5.3.8 Feeding Rate 119
5.4 Lipids and Organic Acids 119
5.5 Proteins 120
5.6 Inorganic Elements 121
5.7 Behavioral Effects 123
5.8 Reproduction 123
5.8.1 Host Castration 123
5.8.2 Nutritional Resources 125
5.8.3 Proteins 125
5.8.4 Physical Damage 126
5.8.5 Accessory Sexual Organs 126
5.8.6 Bioamines 126
5.8.7 Neuroendocrine Interference 127
5.8.8 Male Role in Mating 127
5.8.9 Egg Viability 127
5.8.10 Miracidial Dose 128
5.8.11 Behavior 128
5.9 Gene Regulation 129
5.10 Concluding Remarks 129
References 130
Chapter 6: Effects of Nonschistosome Larval Trematodes on Biomphalaria Snails 135
6.1 Introduction 135
6.2 Biomphalaria spp. as Intermediate Host of Nonschistosome Larval Trematodes 136
6.2.1 As First Intermediate Host 136
6.2.2 As Second Intermediate Host 145
6.3 Effects of Nonschistosome Larval Trematodeson Biomphalaria spp. 147
6.4 Antagonism Between Nonschistosome Trematodesand Schistosomes in Biomphalaria spp. 149
6.5 Immunology of the Infections 150
6.5.1 Immunological Interactions Between Biomphalaria spp. and Nonschistosomes Larval Trematodes 150
6.5.2 Echinostome-Mediated Interference of B. glabrataImmune Defense System 153
6.6 Genomics and Proteomics of the Infections 154
6.7 Molecular Detection of Trematodes in Biomphalaria spp. 156
6.8 Concluding Remarks 157
References 158
Chapter 7: Immunobiology of Biomphalaria–Trematode Interactions 166
7.1 Introduction 166
7.1.1 Why Study Biomphalaria? 166
7.1.2 Biomphalaria/Schistosoma Compatibility and Immunobiological Studies 167
7.2 Back to Basics: Components of Biomphalaria Innate Immunity 168
7.2.1 Cellular Components 169
7.2.2 Immune Recognition 170
7.2.3 Cell-Associated and Plasma-Associated Pattern Recognition Receptors 172
7.2.4 Other Immune-Related Plasma Components 173
7.3 Immune Interactions Between Trematodes and Biomphalaria 174
7.3.1 Encapsulation and Larval Killing In Vivo and In Vitro 174
7.3.1.1 Methods of Investigating Immune Interactions 174
7.3.2 Recognition and Initial Triggering of Encapsulation Responses 176
7.3.2.1 Immune Signaling Pathways 177
7.3.2.2 Consequences of Parasite Recognition:Effector Mechanisms 178
7.4 Anti-immune Counter-Measures by Parasites 179
7.4.1 Mimicry or Immunological Smokescreen 179
7.4.2 Direct Interference with Immune Effector Cell Function 180
7.4.2.1 Echinostome Versus Schistosome: Mechanisms of Survival 180
7.4.2.2 Antioxidant Molecules in ESP/LTP Associated with Larval Protection 181
7.4.2.3 Role of Endogenous Antioxidant Enzyme Systems Against External Oxidative Stress 183
7.4.2.4 Interference with Signaling Pathways 183
7.5 Conclusions and Future Directions 184
7.5.1 General Conclusions 184
7.5.2 Critical Research Areas for Future Progress 185
7.5.2.1 Achievements of Genome Sequencing Efforts 185
7.5.2.2 Investigate Host–Parasite Interactomes 186
7.5.2.3 Development of Tools for Functional Studies 186
7.5.2.4 Address the Question of Interaction Polymorphism 187
References 187
Chapter 8: Advances in the Genomics and Proteomics of the Freshwater Intermediate Snail Host of Schistosoma mansoni, Biomphalaria glabrata 197
8.1 Introduction 198
8.2 Genetics of the B. glabrata Snail/Schistosome Interaction 199
8.3 Snail Innate Defense 201
8.4 Stress Response in Snail/Schistosome Interactions 205
8.5 Proteolytic and Redox Enzymes and Snail/Schistosome Interactions 208
8.6 Characteristics of the B. glabrata Genome 210
8.6.1 Genome Complexity 210
8.6.2 Genome Plasticity and Mobile Genetic Elements 212
8.6.3 Inter- and Intra-Snail-Stock Polymorphisms 213
8.7 Concluding Remarks 213
References 214
Chapter 9: The Biological Control of the Snail Hosts of Schistosomes: The Role of Competitor Snails and Biological Invasions 220
9.1 Introduction 221
9.2 Field Experiments Using the Ampullariid Snail Marisa cornuarietis 222
9.3 Field Experiments Using Thiarid Snails 225
9.4 Snail Invaders and French Antillean Islands: The Decline of Biomphalaria glabrata 229
9.5 Freshwater Snail Invasions: Threats for Environment and Biodiversity? 235
9.6 Concluding Remarks 238
References 239
Index 244