近年來,隨著中國經(jīng)濟(jì)的快速發(fā)展和人民生活水平的不斷提高,人們對(duì)肉、蛋、奶等的需求量也在逐年增加,從而進(jìn)一步促進(jìn)了畜禽養(yǎng)殖業(yè)的蓬勃發(fā)展。然而于此同時(shí),家禽和家畜也是致病性大腸桿菌最重要的宿主來源;尤其是隨著現(xiàn)代牧業(yè)規(guī)模化養(yǎng)殖中抗生素的大量使用,包括致病性大腸桿菌在內(nèi)的多種微生物在藥物的不斷篩選作用下,其耐藥性逐漸增強(qiáng)并不斷出現(xiàn)新的耐藥基因。為此,很多國家或地區(qū)都建立了多種監(jiān)控和調(diào)查研究系統(tǒng)以期最大限度地降低和減少細(xì)菌耐藥性,其中就包括通過對(duì)細(xì)菌的表型水平(如流行病學(xué)調(diào)查)和基因水平(如全基因組測(cè)序)的研究進(jìn)一步了解其耐藥性的進(jìn)化、形成以及傳播機(jī)制等。粘菌素一直被認(rèn)為是治療多種細(xì)菌性感染的最后一道防線,但是近期多種粘菌素的耐藥基因(mcr-1,mcr-2,mcr-3,mcr-4,mcr-5)被發(fā)現(xiàn),給人類和動(dòng)物的健康帶來了巨大的威脅。一、大腸桿菌耐藥性檢測(cè)在2004-2012年間,相關(guān)人員從臨床送檢動(dòng)物雞、鴨、豬、牛等中共分離培養(yǎng)862株致病性大腸桿菌,并通過18種藥敏紙片對(duì)其耐藥性進(jìn)行了檢測(cè)。其中94%的菌株表現(xiàn)為至少對(duì)一種藥物耐藥,83%的菌株對(duì)3種以上的藥物耐藥。絕大部分的菌株對(duì)四環(huán)...

【文章頁數(shù)】：164 頁

【學(xué)位級(jí)別】：博士

【文章目錄】：
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



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