声明
摘要
ABSTRACT
Table of Contents
Abbreviations
CHAPTER Ⅰ：Introduction
1．1．Antibiotic resistance in S．aureus
1．2．Persister cells
1．2．1．MRSA Persister cells formation
1．3．What is a toxin-antitoxin system?
1．3．1．Types of toxin-antitoxin systems
1．3．2．The present scernio of S．aureus toxin-antitoxin(TA) system
1．3．3．Persister cells association with the toxin-antitoxin system
1．4．Type seven secretion system
1．5．Efflux proteins
1．5．1．Multi-drug resistant efflux pump
1．5．3．NorB／C／D Multidrug efflux pumps
1．6．Casino-lytic protease(ClpP)
1．7．The research gap
1．8． Summary of accomplishment
CHAPTER Ⅱ：Materials and methodology
2．1．Bacterial strains，plasmids，media，buffer and growth conditions
2．2．Polymerase chain reaction(PCR)
2．4． Cellular Toxicity assay
2．５．Persistence assay
2．6．Construction of the mutant strains
2．7．Electrophoretic mobility shift assay(EMSA)
2．8．In-vitro transcription
2．9．RNA sequencing
2．11．RNA isolation and real-time,quantitative reverse transcription(qRT-PCR)
CHAPTER Ⅲ：RESULTS
3．1．Staphylococcus aureus genome has a rich profusion of toxin-antitoxin (TA)genes
3．2．Pathogenicity Island (PAI) and non-pathogenicity island TA systems
3．3．A new three-component type-Ⅰregulator-toxin-antitoxin system
3．3．1．Mechanism of interaction between toxin and antitoxin
3．4．Intrinsic activation of TMSS TA system
3．5．Identification of homologues of TMSS TA system
3．6．Ectopic induction of toxin，antitoxin and regulator genes in MRSA
3．6．1．Ectopic induction on ATC inducible plates
3．7．Half-life of TMSS TA system
3．8．Toxin induction decreased persister cells formation in MRSA
3．9．Complete selective eradication of MRSA Persister cells
3．10．Toxin creates an intracellular state of menace
3．10．1．Inhibition of type seven secretion system(T7SS)
3．11．MDR NorA suppression by toxin ectopic induction
3．12．Na+／H+ antiporters system
3．13．Toxin targets 50S ribosomal proteins
3．14．ClpP is activated upon toxin ininduction
3．15．The benefits of TMSS TA system to S．aureus
CHAPTER(Ⅳ)Conclusion
CHPATER(Ⅴ)Discussion
Acknowledgment
Publications
Appendix
References
