표제지
목차
Abstract 11
Chapter Ⅰ. Edwardsiella piscicida 균주의 혈청형 관련 유전자 연구 13
1. 서론 14
2. 재료 및 방법 17
2.1. 사용균주 및 배양조건 17
2.2. 혈청형 시험 20
2.3. 혈청형 관련 유전자 탐색 21
3. 결과 33
3.1. Microtiter agglutination 시험 결과 33
3.2. Whole genome sequencing결과 35
3.3. 혈청형 관련 유전자 37
4. 고찰 41
Chapter Ⅱ. 한국에서 분리된 Edwardsiella piscicida의 항생제 감수성 패턴 및 레지스톰 분석 47
1. 서론 48
2. 재료 및 방법 51
2.1. 사용균주 51
2.2. 항생제 감수성 시험 58
2.3. 역학적 내성 기준값 설정 59
2.4. Antibiotic resistome 분석 60
3. 결과 65
3.1. E. piscicida의 항생제 감수성 패턴 65
3.2. E. piscicida의 Antibiotic resistome 78
4. 고찰 88
Reference 94
Table 1-1. Isolates used for microtiter agglutination test 18
Table 1-2. Bacterial isolates used for anti-serum preparation 21
Table 1-3. Information of 39 genome sequences used in this study 24
Table 1-4. Antigen-related genes used in this study 27
Table 1-5. Agglutination titers of Edwardsiella piscicida strains isolated from different fish species 34
Table 1-6. Summary of genome data sequenced in this study. 36
Table 1-7. Amino acid sequence variation in antigen-encoding genes of olive flounder versus eel-derived strains. 39
Table 2-1. Isolates used for minimum inhibitory concentration (MIC) test and resistance gene PCR 52
Table 2-2. Antibiotics and the range of concentrations used for MIC determination 59
Table 2-3. Oligonucleotides primers used in current study 62
Table 2-4. MIC values for seven antimicrobials against E. piscicida (n=199). 66
Table 2-5. Antimicriobial resistance gene in E. piscicida 79
Table 2-6. Amino substitutions in the GyrA, GyrB, ParC and ParE of E. piscicida. 82
Table 2-7. Overview of the fluoroquinolone resistance mechanisms (QRDR and PMQR) 87
Figure 1-1. Split-violin diagrams presenting agglutination titers against anti-ETW41 (left violins) and anti-KE5 (right violins). 34
Figure 1-2. The structure of E. piscicida O-antigen biosynthesis genes cluster. 39
Figure 1-3. Phylogenetic relationships of 39 E. piscicida. Phylogenetic tree was constructed using concatenated alignment of fepE, glycosyltransferase, wzzB,... 40
Figure 2-1. Percentage frequency of MIC values and epidemiological cut-off values (COWT) for 8 antibiotics against 199 E. piscicida isolates.[이미지참조] 73
Figure 2-2. AMR gene content and AMR phenotypes in 199 E. piscicida isolates. (A) AMR profiles grouped by the drug class to which E. piscicida strains were phenotypically resistant. (B) AMR-associated gene content of E. piscicida strains. Genes detected in the genomes associated with AMR... 75
Figure 2-3. Distribution of proportion of E. piscicida non-wild type (NWT) population (%) against seven antibiotics according to isolation years. The color of dots indicates NWT proportion, while the size of which indicates the number in respective isolation year. 76
Figure 2-4. Distribution of minimum inhibitory concentration of 199 E. piscicida isolates to Amoxicillin (A), Cephalexcin (B), Ceftiofur (C), Oxytetracycline (D), Oxolinic acid (E), Enrofloxacin (F), Florfenicol (G) and Trimethoprim/sulfadiazine (H) shown... 86