Title Page
Contents
Abstract 8
INTRODUCTION 10
MATERIALS AND METHODS 13
2.1. Sample collection 13
2.2. Isolation of antibiotic resistant bacteria 16
2.3. PCR amplification and sequencing of Antibiotic resistant bacteria 16
2.3.1. DNA extraction 16
2.3.2. Sequencing 17
2.4. Determination of Minimum Inhibitory Concentration (MIC) 18
2.5. Antibiotic susceptibility test 18
2.6. Plasmid isolation and conjugation 19
RESULTS 21
3.1. Isolation of antibiotic resistant bacteria 21
3.2. Identification of Antibiotic resistant bacteria strains 27
3.3. Minimum Inhibitory Concentrations (MICs) 28
3.4. Antibiotic susceptibility test 29
3.5. Plasmid isolation and conjugation 33
DISCUSSION 36
REFERENCES 42
Table 1. Summary of sample collection 14
Table 2. Primers used in the different PCR assays 20
Table 3. Bacterial counts of different samples on different single antibiotics. 22
Table 4. Bacteria counts on double antibiotics combinations. 23
Table 5. Bacteria counts on triple antibiotics combinations 24
Table 6. Antibiotic test results for the different bacterial isolates on single and combined antibiotics 26
Table 7. Identification of different antibiotic resistant bacteria 27
Table 8. MIC results for the resistant strains 28
Table 9. Disk diameters and susceptibility test results for glucose non-fermenting bacteria 30
Table 10. Disk diameters and susceptibility test results for glucose fermenting bacteria 31
Fig. 1. A map of South Korea showing location of sampling sites. 15
Fig. 2. Inhibition zones of selected bacteria strains and antibiotics. A and B are Aztreonam and... 32
Fig. 3. Conjugation of antibiotics resistant S3TSV5 and E.coli J53. A- donor strain on... 35
Fig. 4. Confirmation of conjugation mediated plasmid transfer between antibiotics resistant... 35