Title Page
ABSTRACT
국문 초록
Contents
CHAPTER 1. INTRODUCTION 14
CHAPTER 2. REVIEW OF LITERATURE 17
2.1. Peaches 17
2.1.1. Characteristics of peaches 17
2.1.2. Foodborne illness outbreaks or recalls of products related to peaches 20
2.2. Nectarines 21
2.2.1. Characteristics of nectarines 21
2.2.2. Foodborne illness outbreaks or recalls of products related to nectarines 23
2.3. Foodborne pathogens 24
2.3.1. Characteristics of Salmonella Typhimurium 24
2.3.2. Characteristics of Escherichia coli O157:H7 27
2.3.3. Characteristics of Staphylococcus aureus 31
2.3.4. Characteristics of Listeria monocytogenes 34
2.3.5. Characteristics of Bacillus cereus 37
2.4. Scanning electron microscopy 41
2.4.1. Characteristics of scanning electron microscopy 41
2.4.2. Specimen for scanning electron microscopy 43
CHAPTER 3. MATERIALS AND METHODS 44
3.1. Bacterial strains and preparation of bacterial cell suspensions 44
3.2. Preparation of peaches and nectarines 45
3.3. Inoculation and storage of peaches and nectarines 46
3.4. Microbiological analysis 47
3.5. Recovery confirmation of injured cell 48
3.6. Scanning electron microscopy (SEM) analysis of peaches and nectarines 49
3.7. Statistical analysis 50
CHAPTER 4. RESULTS 51
4.1. Survival of foodborne pathogens on the inoculated peaches 51
4.2. Survival of foodborne pathogens on the inoculated nectarines 56
4.3. Scanning electron microscopy (SEM) image of foodborne pathogens attached to peach and nectarine samples 58
CHAPTER 5. DISCUSSION 61
REFERENCES 66
Table 1. World production of peaches from 1980 to 2008 19
Table 2. Properties of foodborne illnesses associated with Bacillus cereus 39
Table 3. Recovery of foodborne pathogens inoculated on the surfaces of peach and nectarine samples at low concentrations (ca. 1-2 log CFU/g) and stored at 5°C during 14 days 53
Figure 1. Transmission of Salmonella spp. between reservoirs and humans. 26
Figure 2. Six categories of pathogenic Escherichia coli. 29
Figure 3. Transmission of Escherichia coli O157:H7 between reservoirs and humans. 30
Figure 4. Transmission of Staphylococcus aureus between reservoirs and humans. 33
Figure 5. Transmission of Listeria monocytogenes between reservoirs and humans. 36
Figure 6. Transmission of Bacillus cereus between reservoirs and humans. 40
Figure 7. Schematic diagram of the key components of SEM. 42
Figure 8. Survival of foodborne pathogens (Salmonella Typhimurium, Escherichia coli O157:H7, Staphylococcus aureus, Listeria monocytogenes, and Bacillus cereus) inoculated peaches and... 54
Figure 9. Survival of foodborne pathogens (Salmonella Typhimurium, Escherichia coli O157:H7, Staphylococcus aureus, Listeria monocytogenes, and Bacillus cereus) inoculated peaches and... 55
Figure 10. High resolution scanning electron micrographs of foodborne pathogens (Salmonella Typhimurium, Escherichia coli O157:H7, Staphylococcus aureus, Listeria monocytogenes, and... 59
Figure 11. High resolution scanning electron micrographs of foodborne pathogens (Salmonella Typhimurium, Escherichia coli O157:H7, Staphylococcus aureus, Listeria monocytogenes, and... 60