發(fā)布時間：2024-02-28 01:12

　　副豬嗜血桿菌(HPS,H.parasuis)是一種能引起豬的格拉瑟氏病革蘭氏陰性細(xì)菌,依賴于煙酰胺腺嘌呤二核苷酸生長,,其導(dǎo)致的臨床特征主要是纖維素性多發(fā)性漿膜炎、腦膜炎和關(guān)節(jié)炎。越南的生豬產(chǎn)量在世界上排名第五,到目前為止,關(guān)于越南HPS的流行病學(xué)特征、耐藥性(AMR)和耐藥性基因(ARGs)的流行情況尚缺乏相關(guān)數(shù)據(jù)。此外,用于預(yù)防和控制格拉瑟氏病的疫苗在越南尚未開發(fā)。本課題研究包括一下內(nèi)容:本課題第一部分主要研究了從越南中部廣平省和順化省豬場中分離到的HPS菌株的血清型流行性和毒力相關(guān)基因(VGs)的分布。我們從814個肺和鼻腔拭子樣本中分離出56株HPS(6.9%).不同地區(qū)、不同年齡、不同產(chǎn)地標(biāo)本的分離率差異有統(tǒng)計學(xué)意義(p<0.05)。采用一步多重PCR(m PCR)方法鑒定了這些菌株的血清型。結(jié)果表明,主要流行血清型為5型(15/56,26.8%),其次是血清型2型(13/56,23.2%)和4型(10/56,17.9%)。在這些HPS菌株中檢測并分析了9個毒力相關(guān)基因(VGs),其中vta1基因(35/56,62.5%)檢出率最高,其次是vta3基因(24/56,42...

【文章頁數(shù)】：142 頁

【學(xué)位級別】：博士

【文章目錄】：
Abstract
摘要
Abbreviations used in this dissertation
CHAPTER 1 General introduction and literature review
    1.1 General introduction
        1.1.1 Pig production in China and Vietnam
        1.1.2 Haemophilus parasuis
        1.1.3 Antimicrobial resistance
        1.1.4 Haemophilus parasuis vaccines
        1.1.5 Serial passage,live-attenuated Haemophilus parasuis vaccines
    1.2 Significance of the study
    1.3 General literature review
        1.3.1 Etiology of Haemophilus parasuis
        1.3.2 Cultivation and biochemical characteristics
        1.3.3 Serotypes of Haemophilus parasuis
        1.3.4 Pathogenesis mechanisms of Haemophilus parasuis
        1.3.5 Virulence factors
            1.3.5.1 Outer membrane proteins
            1.3.5.2 Virulence-associated trimeric autotransporters
            1.3.5.3 Oligopeptide binding protein Opp A
            1.3.5.4 Cytolethal distending toxin
            1.3.5.5 Lipooligosaccharide
            1.3.5.6 Type V secretion system
        1.3.6 Epidemiology of Gl?sser’s disease
        1.3.7 Clinical symptoms
        1.3.8 Pathological lesions
        1.3.9 Diagnosis methods
            1.3.9.1 Isolation and identification of bacteria from clinical samples
            1.3.9.2 Serotyping
            1.3.9.3 Genotyping
            1.3.9.4 Antibody detection and molecular biological methods
        1.3.10 Treatment and prevention
            1.3.10.1 Antimicrobial therapy
            1.3.10.2 Vaccination
        1.3.11 Antimicrobial resistance of Haemophilus parasuis
        1.3.12 Mechanisms of antimicrobial resistance
        1.3.13 Serial passage bacteria for development live-attenuated vaccines
CHAPTER 2 Characterization of serotypes and virulence genes of Haemophilus parasuis isolates from swine in Quang Binh and Thua Thien Hue provinces,Vietnam
    2.1 Introduction
    2.2 Materials and methods
        2.2.1 Nicotinamide adenine dinucleotide preparation
        2.2.2 Media preparation
        2.2.3 Sample collection
        2.2.4 Isolation and identification of bacteria
        2.2.5 Serotyping
        2.2.6 Virulence genes identification
        2.2.7 Data analysis
    2.3 Result
        2.3.1 Prevalence of Haemophilus parasuis strains in Central Vietnam
        2.3.2 Distribution of Haemophilus parasuis serotypes
        2.3.3 Virulence gene analysis of the Haemophilus parasuis strains
        2.3.4 Association between serotypes,characteristic serotypes,and virulence genes
    2.4 Discussion
CHAPTER 3 Vaccine against the Vietnamese Strains Prevalence of phenotypes and genotypes of antimicrobial resistance and their relationship in Haemophilus parasuis isolates from swine in Quang Binh and Thua Thien Hue Provinces,Vietnam
    3.1 Introduction
    3.2 Materials and methods
        3.2.1 Bacterial isolates
        3.2.2 Antimicrobial susceptibilities
        3.2.3 Antimicrobial resistance gene amplification
        3.2.4 Data analysis
    3.3 Results
        3.3.1 AMR phenotypes of Haemophilus parasuis strains
        3.3.2 Associations among antimicrobial resistance phenotypes
        3.3.3 Antimicrobial resistance genes of H.parasuis strains
        3.3.4 Associations among resistance genes
        3.3.5 Associations between phenotypes and genotypes of antimicrobial resistance
    3.4 Discussion
CHAPTER 4 Characterization of in vitro serially passaged strains of Haemophilus parasuis
    4.1 Introduction
    4.2 Materials and methods
        4.2.1 Serial passaging
        4.2.2 Growth assay
        4.2.3 Assessment attenuation virulence of sub-strains
            4.2.3.1 Animals and housing
            4.2.3.2 Guinea pig infection assay
            4.2.3.3 Piglet infection assay
            4.2.3.4 Animal monitoring and pathological examination
        4.2.4 Data analysis
    4.3 Results
        4.3.1 Growth
            4.3.2.1 Guinea pig infection model
            4.3.2.2 Piglet infection model
    4.4 Discussion
CHAPTER 5 Efficacy of commercial Chinese inactivated vaccine against experimental challenge with Haemophilus parasuis serotype4 and5 isolates from Central Vietnam
    5.1 Introduction
    5.2 Materials and methods
        5.2.1 Bacterial and vaccine
        5.2.2 Animals,vaccination and challenge of guinea pigs
        5.2.3 Tissues bacterial loads
        5.2.4 Antibody detected
        5.2.5 Cytokine stimulation assay
        5.2.6 Statistical analysis
    5.3 Results
        5.3.1 Serological analysis
            5.3.1.1 Analysis of antibody titers in guinea pigs
            5.3.1.2 Effect of vaccination on INF-g,IL-4 levels and IFN-γ-to-IL-4 ratio in sera of guinea pigs
        5.3.2 Protective efficacy against lethal challenge with H.parasuis serotypes4and5
    5.4 Discussion
Chapter 6 Conclusion
References
Publications
Acknowledgments



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