奶牛乳房炎金黄色葡萄球菌与化脓隐秘杆菌的生存策略：耐药性、生物膜以及小菌落突变株
发布时间：2022-07-20 17:06
奶牛乳房炎是一种主要由病原微生物引起的奶牛疾病,在世界各地都有发生。感染后奶牛奶产量的下降,甚至是慢性感染牛的淘汰,都给奶牛养殖业造成巨大的经济损失。病原微生物能穿透乳头管,并在泌乳腔中繁殖,进而引起乳房炎。多数乳房炎病例是由一个相对小群体的细菌造成的,包括金黄色葡萄球菌,乳房链球菌,大肠杆菌和隐秘化脓杆菌等。奶牛乳房炎指的是乳腺的炎症,炎症严重程度取决于病原体和宿主反应。这些病原微生物会发生进化,并通过许多战略抵制抗生素的作用和得以生存。小菌落突变株和生物膜的形成,以及介导灭活酶的基因表达,都是细菌逃避抗生素作用的生存策略。进化后的细菌常常能引起持续感染的奶牛乳房炎。在本研究中,我们从临床与亚临床型奶牛乳房炎（第二章与第三章）,慢性与复发性奶牛乳房炎（第四章）分离出金黄色葡萄球菌和隐秘化脓棒状杆菌,并对其毒力因子,生物膜的形成,小菌落突变体（small colony variants,SCVs）的形成,耐药基因,以及耐药特征进行了检测与分析。研究一：本文着重研究35株在两个奶牛场内分离到的金黄色葡萄球菌的流行情况,测定金黄色葡萄球菌的耐药性,尤其是青霉素和甲氧西林,并研究金黄色葡萄球...
【文章页数】：140 页
【学位级别】：博士
【文章目录】：
中文摘要
Abstract
ABBREVIATIONS
Chapter 1 REVIEW OF THE LITERATURE
1.1 MASTITIS
1.1.1 Description
1.1.2 The Mammary Gland
1.1.3 Mammary Epithelial Cells(MEC)
1.2 Mastitis Pathogens
1.2.1 Staphylococcus aureus
1.2.2 Trueperella (Arcanobacterium) pyogenes
1.3 Bacterial survival strategies
1.3.1 Antibiotic resistance
1.3.2 Forming biofilm (slime)
1.3.3 Forming small colony variants (SCVs)
1.3.4 Searching for novel antibiotics targets
1.4 Objective and meaning of the studies described in this Ihesis
Chapter 2:Properties of Staphylococcus aureus Isolated from Mastitis at twoDairy Herds in China
2.1 Molecular methods for PCR-mediated identification
2.1.1 16S rRNA gene
2.1.2 Random amplified polymorphic DNA (RAPD)
2.2 The role of bacterial virulence factors in Staphylococcus aureus intramammaryinfection
2.2.1 Control and expression of virulence factors
2.2.2 Virulence factors involved in establishing an infection
2.2.3 Virulence factors involved in maintenance of infection
2.3 Staphylococcal biofilm formation
2.3.1 Molecules responsible for exopolysaccharide production
2.3.2 PIA production and the intracellular adhesion locus
2.4 Antimicrobial resistance of bovine Staphylococcus aureus
2.5 Materials and methods
2.5.1 Origin of S. aureus isolates
2.5.2 Study animals and herds
2.5.3 Clinical examination of the cows and mastitis follow-up
2.5.4 Sample collection
2.5.5 Bacterial isolation and conventional identification
2.5.6 Biofilm formation
2.5.7 DNA extraction and preparation
2.5.8 Detection of genes encoding virulence and adhesion factors using PCR
2.5.9 Detection of ica locus by PCR
2.5.10 Antimicrobial susceptibility testing
2.6 Results
2.6.1 Bacterial isolation and conventional identification
2.6.2 Random amplified polymorphic DNA (RAPD)
2.6.3 Biofilm formation
2.6.4 S.aureus virulence gene profiles
2.6.5 Detection of ica locus by PCR
2.6.6 Antimicrobial resistance of S.aureus
2.7 Discussion
2.8 Conclusion
Chapter3:Characteristics of Trueperella pyogenes isolated from bovinemastitis
3.1 Putative virulence factors of A.(T.) pyogenes
3.1.1 Pyolysin
3.1.2 Collagen-binding proteins
3.1.3. Exoenzymes
3.1.4 Fimbriae
3.1.5 Hemolytic properties and CAMP-like hemolytic reactions
3.2 Materials and methods
3.2.1 Isolation and identification of T. pyogenes from milk samples
3.2.2 Identification and further characterization of the bacteria by conventional methods
3.2.3 Biochemical tests
3.2.4 Growth curve
3.2.5 Growth on Loeffler medium
3.2.6 Identification and molecular characterization of the bacteria by PCR
3.2.7 Detection of potential virulence factor and antibiotic resistance genes
3.2.8 Biofilm production
3.2.9 Antibiotic resistance
3.2.10 Intracellular assessment of T. pyogenes
3.2.11 Preservation of the bacteria
3.3 Results
3.3.1 Isolation and identification of T. pyogenes from milk
3.3.2 Biochemical properties and CAMP-like hemolytic reactions
3.3.3 Growth curve
3.3.4 Analysis of DNA amplification products obtained by RAPD
3.3.5 Biofilm production
3.3.6 Antibiotic resistance
3.3.7 Intracellular assessment of T. pyogenes
3.3.8 Genes encoding potential virulence factors
3.4 Discussion
3.5 Conclusion
CHAPTER 4:Characteristics of Staphylococcus aureus and Trueperellapyogenes-Small Colony Variants and their Parent Strains Isolated fromChronic Mastitis
4.1 Characteristics of Staphylococcus aureus Small Colony Variant and Its Parent Strain Isolated from Chronic Mastitis
4.1.1 Project aims
4.1.2 Materials and methods
4.1.3 Results
4.1.4 Discussion
4.1.5 Conclusion
4.2 Isolation and characterization of novel Trueperella pyogenes small colony variants from bovine mastitis cases
4.2.1 Project aims
4.2.2 Materials and methods
4.2.3 Results
4.2.4 Discussion
4.2.5 Conclusion
Chapter 5:Conclusions
References
Acknowledgement
个人简历
本文编号：3664393
【文章页数】：140 页
【学位级别】：博士
【文章目录】：
中文摘要
Abstract
ABBREVIATIONS
Chapter 1 REVIEW OF THE LITERATURE
1.1 MASTITIS
1.1.1 Description
1.1.2 The Mammary Gland
1.1.3 Mammary Epithelial Cells(MEC)
1.2 Mastitis Pathogens
1.2.1 Staphylococcus aureus
1.2.2 Trueperella (Arcanobacterium) pyogenes
1.3 Bacterial survival strategies
1.3.1 Antibiotic resistance
1.3.2 Forming biofilm (slime)
1.3.3 Forming small colony variants (SCVs)
1.3.4 Searching for novel antibiotics targets
1.4 Objective and meaning of the studies described in this Ihesis
Chapter 2:Properties of Staphylococcus aureus Isolated from Mastitis at twoDairy Herds in China
2.1 Molecular methods for PCR-mediated identification
2.1.1 16S rRNA gene
2.1.2 Random amplified polymorphic DNA (RAPD)
2.2 The role of bacterial virulence factors in Staphylococcus aureus intramammaryinfection
2.2.1 Control and expression of virulence factors
2.2.2 Virulence factors involved in establishing an infection
2.2.3 Virulence factors involved in maintenance of infection
2.3 Staphylococcal biofilm formation
2.3.1 Molecules responsible for exopolysaccharide production
2.3.2 PIA production and the intracellular adhesion locus
2.4 Antimicrobial resistance of bovine Staphylococcus aureus
2.5 Materials and methods
2.5.1 Origin of S. aureus isolates
2.5.2 Study animals and herds
2.5.3 Clinical examination of the cows and mastitis follow-up
2.5.4 Sample collection
2.5.5 Bacterial isolation and conventional identification
2.5.6 Biofilm formation
2.5.7 DNA extraction and preparation
2.5.8 Detection of genes encoding virulence and adhesion factors using PCR
2.5.9 Detection of ica locus by PCR
2.5.10 Antimicrobial susceptibility testing
2.6 Results
2.6.1 Bacterial isolation and conventional identification
2.6.2 Random amplified polymorphic DNA (RAPD)
2.6.3 Biofilm formation
2.6.4 S.aureus virulence gene profiles
2.6.5 Detection of ica locus by PCR
2.6.6 Antimicrobial resistance of S.aureus
2.7 Discussion
2.8 Conclusion
Chapter3:Characteristics of Trueperella pyogenes isolated from bovinemastitis
3.1 Putative virulence factors of A.(T.) pyogenes
3.1.1 Pyolysin
3.1.2 Collagen-binding proteins
3.1.3. Exoenzymes
3.1.4 Fimbriae
3.1.5 Hemolytic properties and CAMP-like hemolytic reactions
3.2 Materials and methods
3.2.1 Isolation and identification of T. pyogenes from milk samples
3.2.2 Identification and further characterization of the bacteria by conventional methods
3.2.3 Biochemical tests
3.2.4 Growth curve
3.2.5 Growth on Loeffler medium
3.2.6 Identification and molecular characterization of the bacteria by PCR
3.2.7 Detection of potential virulence factor and antibiotic resistance genes
3.2.8 Biofilm production
3.2.9 Antibiotic resistance
3.2.10 Intracellular assessment of T. pyogenes
3.2.11 Preservation of the bacteria
3.3 Results
3.3.1 Isolation and identification of T. pyogenes from milk
3.3.2 Biochemical properties and CAMP-like hemolytic reactions
3.3.3 Growth curve
3.3.4 Analysis of DNA amplification products obtained by RAPD
3.3.5 Biofilm production
3.3.6 Antibiotic resistance
3.3.7 Intracellular assessment of T. pyogenes
3.3.8 Genes encoding potential virulence factors
3.4 Discussion
3.5 Conclusion
CHAPTER 4:Characteristics of Staphylococcus aureus and Trueperellapyogenes-Small Colony Variants and their Parent Strains Isolated fromChronic Mastitis
4.1 Characteristics of Staphylococcus aureus Small Colony Variant and Its Parent Strain Isolated from Chronic Mastitis
4.1.1 Project aims
4.1.2 Materials and methods
4.1.3 Results
4.1.4 Discussion
4.1.5 Conclusion
4.2 Isolation and characterization of novel Trueperella pyogenes small colony variants from bovine mastitis cases
4.2.1 Project aims
4.2.2 Materials and methods
4.2.3 Results
4.2.4 Discussion
4.2.5 Conclusion
Chapter 5:Conclusions
References
Acknowledgement
个人简历
本文编号：3664393
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