粘菌素耐药基因（mcr）的分子流行病学和传播特性的研究
发布时间：2023-10-21 16:10
近年来,随着中国经济的快速发展和人民生活水平的不断提高,人们对肉、蛋、奶等的需求量也在逐年增加,从而进一步促进了畜禽养殖业的蓬勃发展。然而于此同时,家禽和家畜也是致病性大肠杆菌最重要的宿主来源;尤其是随着现代牧业规模化养殖中抗生素的大量使用,包括致病性大肠杆菌在内的多种微生物在药物的不断筛选作用下,其耐药性逐渐增强并不断出现新的耐药基因。为此,很多国家或地区都建立了多种监控和调查研究系统以期最大限度地降低和减少细菌耐药性,其中就包括通过对细菌的表型水平(如流行病学调查)和基因水平(如全基因组测序)的研究进一步了解其耐药性的进化、形成以及传播机制等。粘菌素一直被认为是治疗多种细菌性感染的最后一道防线,但是近期多种粘菌素的耐药基因(mcr-1,mcr-2,mcr-3,mcr-4,mcr-5)被发现,给人类和动物的健康带来了巨大的威胁。一、大肠杆菌耐药性检测在2004-2012年间,相关人员从临床送检动物鸡、鸭、猪、牛等中共分离培养862株致病性大肠杆菌,并通过18种药敏纸片对其耐药性进行了检测。其中94%的菌株表现为至少对一种药物耐药,83%的菌株对3种以上的药物耐药。绝大部分的菌株对四环...
【文章页数】：164 页
【学位级别】：博士
【文章目录】：
ABSTRACT
摘要
LIST OF ABBREVIATION AND SYMBOLS
CHAPTER 1: LITERATURE REVIEW
1.0 INTRODUCTION
1.1 ESCHERICHIA COLI
1.1.1 Biology and biochemistry
1.1.2 Diversity of E. coli strains
1.1.3 Genomics
1.1.4 Pathogenic Escherichia coli strains
1.1.5 Antibiotic therapy and resistance
1.2 ANTIMICROBIAL RESISTANCE
1.2.1 Definition
1.2.2 Modes of antimicrobial action
1.2.3 Types of resistance
1.2.4 Mechanisms of resistance to antimicrobials
1.3 RESISTANCE AGAINST COLISTIN
1.3.1 Colistin action on Enteobacteriaceae
1.3.2 Mechanisms of Enterobacteriaceae resistance to colistin
1.3.3 Epidemiology of colistin resistance genes
1.4 ROLE OF FLIES IN TRANSMITTING PATHOGENS AND ANTIMICROBIAL RESISTANCEGENES
REFERENCE
CHAPTER 2: ANTIMICROBIAL RESISTANCE IN CLINICAL ESCHERICHLA COLIISOLATES FROM POULTRY AND LIVESTOCK, CHINA
2.1 INTRODUCTION
2.2 MATERIALS AND METHODS
2.2.1 Bacterial isolates
2.2.2 Antimicrobial susceptibility testing
2.2.3 Statistical analysis
2.3 RESULTS
2.4 DISCUSSION
REFERENCE
CHAPTER 3: GENETIC CHARACTERIZATION OF MULTIDRUG RESISTANTCLINICAL ESCHERICHIA COLI ISOLATED FROM POULTRY AND LIVESTOCK,CHINA
3.1 INTRODUCTION
3.2 MATERIALS AND METHODS
3.2.1 Bacterial strains
3.2.2 Genome sequencing and assembly
3.2.3 Identification of resistance genes
3.2.4 MLS Typing and virulence typing
3.2.5 Presence of plasmids
3.3 RESULT
3.3.1 Antibiotic resistance genes
3.3.2 Prevalence of plasmid replicons
3.3.3 Virulence genes and multilocus sequence type (MLST)
3.4 DISCUSSION
REFERENCE
CHAPTER 4: DETECTION OF THE COLISTIN-RESISTANCE GENE MCR-1 INSAMPLES FROM CATTLE, DOGS, PEOPLE, PIGS, AND POULTRY IN CHINA
4.1 INTRODUCTION
4.2 MATERIALS AND METHODS
4.2.1 Ethics statement
4.2.2 Swabs from cattle, dogs, pigs, people and poultry
4.2.3 DNA extraction
4.2.4 PCR assay
4.3 RESULTS
4.3.1 Establishment of the mcr-1 qPCR and the total-bacteria qPCR
4.3.2 Prevalence of mcr-1 in swabs from poultry, pigs, cattle, dogs and people
4.3.3 Quantification of mcr-1 in swabs from poultry, pigs, cattle, dogs and people
4.4 DISCUSSION
REFERENCE
CHAPTER 5: HOUSEFLY (MUSCA DOMESTICA) AND BLOW FLY(PROTOPHORMIA TERRAENOVAE) AS VECTORS OF COLISTIN RESISTANCEGENES-CARRYING BACTERIA
5.1 INTRODUCTION
5.2 MATERIALS AND METHODS
5.2.1 Flies
5.2.2 Bacterial isolates from flies
5.2.3 DNA extraction
5.2.4 PCR assays
5.2.5 Susceptibility testing
5.2.6 Phylogenetic analysis
5.3 RESULTS
5.3.1 Flies
5.3.2 Bacterial isolates from flies
5.3.3 Development of mcr-l-qPCR, mcr-2-qPCR, and mcr-3-qPCR
5.3.4 Prevalence of the mcr-1,mcr-2 and mcr-3 in flies
5.3.5 Prevalence of the mcr-1, mcr-2 and mcr-3 in bacterial isolates
5.3.6 Susceptibility testing
5.3.7 Phylogenetic comparison
5.4 DISCUSSION
REFERENCE
CHAPTER 6: IDENTIFICATION AND CHARACTERIZATION OF MCR MEDIATEDCOLISTIN RESISTANCE IN PATHOGENIC ESCHERICHIA COLI FROM POULTRYAND LIVESTOCK IN CHINA
6.1 INTRODUCTION
6.2 MATERIALS AND METHODS
6.2.1 Bacterial isolates
6.2.2 DNA extraction
6.2.3 mcr-1,mcr-2 and mcr-3 qPCRs
6.2.4 E. coli FRET-qPCR
6.2.5 Colistin susceptibility testing
6.2.6 Determination of in vitro maintenance and transfer of mcr-1 in the presenceand absence of colistin
6.2.7 Statistical analysis
6.3 RESULTS
6.3.1 Development of #wcr-7-qPCR, mcf-2-qPCR, and mcr-5-qPCR
6.3.2 Prevalence of the mcr-1 in pathogenic E. coli
6.3.3 Susceptibility testing
6.3.4 Differentiation of E. coli strain E249 (mcr-1 positive) and E254 (mcr-1negative) with a gyrA FRET-qPCR
6.3.5 Determination of in vitro maintenance and transfer of mcr-1 in the presenceand absence of colistin
6.4 DISCUSSION
REFERENCE
CONCLUSIONS OF THIS STUDY
List of Publication
Acknowledgements
本文编号：3856175
【文章页数】：164 页
【学位级别】：博士
【文章目录】：
ABSTRACT
摘要
LIST OF ABBREVIATION AND SYMBOLS
CHAPTER 1: LITERATURE REVIEW
1.0 INTRODUCTION
1.1 ESCHERICHIA COLI
1.1.1 Biology and biochemistry
1.1.2 Diversity of E. coli strains
1.1.3 Genomics
1.1.4 Pathogenic Escherichia coli strains
1.1.5 Antibiotic therapy and resistance
1.2 ANTIMICROBIAL RESISTANCE
1.2.1 Definition
1.2.2 Modes of antimicrobial action
1.2.3 Types of resistance
1.2.4 Mechanisms of resistance to antimicrobials
1.3 RESISTANCE AGAINST COLISTIN
1.3.1 Colistin action on Enteobacteriaceae
1.3.2 Mechanisms of Enterobacteriaceae resistance to colistin
1.3.3 Epidemiology of colistin resistance genes
1.4 ROLE OF FLIES IN TRANSMITTING PATHOGENS AND ANTIMICROBIAL RESISTANCEGENES
REFERENCE
CHAPTER 2: ANTIMICROBIAL RESISTANCE IN CLINICAL ESCHERICHLA COLIISOLATES FROM POULTRY AND LIVESTOCK, CHINA
2.1 INTRODUCTION
2.2 MATERIALS AND METHODS
2.2.1 Bacterial isolates
2.2.2 Antimicrobial susceptibility testing
2.2.3 Statistical analysis
2.3 RESULTS
2.4 DISCUSSION
REFERENCE
CHAPTER 3: GENETIC CHARACTERIZATION OF MULTIDRUG RESISTANTCLINICAL ESCHERICHIA COLI ISOLATED FROM POULTRY AND LIVESTOCK,CHINA
3.1 INTRODUCTION
3.2 MATERIALS AND METHODS
3.2.1 Bacterial strains
3.2.2 Genome sequencing and assembly
3.2.3 Identification of resistance genes
3.2.4 MLS Typing and virulence typing
3.2.5 Presence of plasmids
3.3 RESULT
3.3.1 Antibiotic resistance genes
3.3.2 Prevalence of plasmid replicons
3.3.3 Virulence genes and multilocus sequence type (MLST)
3.4 DISCUSSION
REFERENCE
CHAPTER 4: DETECTION OF THE COLISTIN-RESISTANCE GENE MCR-1 INSAMPLES FROM CATTLE, DOGS, PEOPLE, PIGS, AND POULTRY IN CHINA
4.1 INTRODUCTION
4.2 MATERIALS AND METHODS
4.2.1 Ethics statement
4.2.2 Swabs from cattle, dogs, pigs, people and poultry
4.2.3 DNA extraction
4.2.4 PCR assay
4.3 RESULTS
4.3.1 Establishment of the mcr-1 qPCR and the total-bacteria qPCR
4.3.2 Prevalence of mcr-1 in swabs from poultry, pigs, cattle, dogs and people
4.3.3 Quantification of mcr-1 in swabs from poultry, pigs, cattle, dogs and people
4.4 DISCUSSION
REFERENCE
CHAPTER 5: HOUSEFLY (MUSCA DOMESTICA) AND BLOW FLY(PROTOPHORMIA TERRAENOVAE) AS VECTORS OF COLISTIN RESISTANCEGENES-CARRYING BACTERIA
5.1 INTRODUCTION
5.2 MATERIALS AND METHODS
5.2.1 Flies
5.2.2 Bacterial isolates from flies
5.2.3 DNA extraction
5.2.4 PCR assays
5.2.5 Susceptibility testing
5.2.6 Phylogenetic analysis
5.3 RESULTS
5.3.1 Flies
5.3.2 Bacterial isolates from flies
5.3.3 Development of mcr-l-qPCR, mcr-2-qPCR, and mcr-3-qPCR
5.3.4 Prevalence of the mcr-1,mcr-2 and mcr-3 in flies
5.3.5 Prevalence of the mcr-1, mcr-2 and mcr-3 in bacterial isolates
5.3.6 Susceptibility testing
5.3.7 Phylogenetic comparison
5.4 DISCUSSION
REFERENCE
CHAPTER 6: IDENTIFICATION AND CHARACTERIZATION OF MCR MEDIATEDCOLISTIN RESISTANCE IN PATHOGENIC ESCHERICHIA COLI FROM POULTRYAND LIVESTOCK IN CHINA
6.1 INTRODUCTION
6.2 MATERIALS AND METHODS
6.2.1 Bacterial isolates
6.2.2 DNA extraction
6.2.3 mcr-1,mcr-2 and mcr-3 qPCRs
6.2.4 E. coli FRET-qPCR
6.2.5 Colistin susceptibility testing
6.2.6 Determination of in vitro maintenance and transfer of mcr-1 in the presenceand absence of colistin
6.2.7 Statistical analysis
6.3 RESULTS
6.3.1 Development of #wcr-7-qPCR, mcf-2-qPCR, and mcr-5-qPCR
6.3.2 Prevalence of the mcr-1 in pathogenic E. coli
6.3.3 Susceptibility testing
6.3.4 Differentiation of E. coli strain E249 (mcr-1 positive) and E254 (mcr-1negative) with a gyrA FRET-qPCR
6.3.5 Determination of in vitro maintenance and transfer of mcr-1 in the presenceand absence of colistin
6.4 DISCUSSION
REFERENCE
CONCLUSIONS OF THIS STUDY
List of Publication
Acknowledgements
本文编号：3856175
本文链接：https://www.wllwen.com/yixuelunwen/dongwuyixue/3856175.html
