Chan, Lap Kwan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 131-147). / Abstracts in English and Chinese. / ACKNOWLEDGEMENTS --- p.i / ABSTRACT --- p.iii / ABSTRACT (CHINESE VERSION) --- p.v / TABLE OF CONTENTS --- p.vii / LIST OF TABLES --- p.xiv / LIST OF FIGURES --- p.xv / LIST OF ABBREVIATIONS --- p.xvii / Chapter CHAPTER 1 --- INTRODUCTION / Chapter 1.1 --- Background --- p.2 / Chapter 1.2 --- Prevalence of antimicrobial reisitance in gonococcal strains --- p.4 / Chapter 1.2.1 --- Prevalence of penicillin resistant gonococcal strains --- p.5 / Chapter 1.2.2 --- Prevalence of tetracycline resistant gonococcal strains --- p.6 / Chapter 1.2.3 --- Prevalence of quinolone resistant gonococcal strains. --- p.7 / Chapter 1.2.4 --- Emergence of generation cephalosporin reduced susceptible gonococcal strains --- p.8 / Chapter 1.2.5 --- Monitoring the prevalence of gonorrhea --- p.9 / Chapter 1.3 --- Gonococcal Antimicrobial Surveillance Program --- p.10 / Chapter 1.4 --- Antimicrobial Resistance Mechanisms in N. gonorrhoeae --- p.11 / Chapter 1.4.1 --- "Innate Resistance Mechanisms in N, gonorrhoeae" --- p.11 / Chapter 1.4.1.1 --- Natural mechanisms in N. gonorrhoeae against toxic substance --- p.11 / Chapter 1.4.1.2 --- Efflux pump inhibitors --- p.13 / Chapter 1.4.2 --- Development of acquired antimicrobial resistance in N. gonorrhoeae --- p.14 / Chapter 1.4.2.1 --- Penicillin --- p.14 / Chapter 1.4.2.1.1 --- Chromosomal-mediated resistance --- p.14 / Chapter 1.4.2.1.2 --- Plasmid-mediated resistance --- p.16 / Chapter 1.4.2.2 --- Tetracycline --- p.16 / Chapter 1.4.2.2.1 --- Plasmid-mediated resistance --- p.17 / Chapter 1.4.2.2.2 --- Chromosomal mediated resistance --- p.18 / Chapter 1.4.2.3 --- Fluroquinolone --- p.18 / Chapter 1.4.2.3.1 --- Resistant mechanism in quinolone resistant gonococcal strains --- p.19 / Chapter 1.4.2.3.1.1 --- gyrA andparC --- p.19 / Chapter 1.4.2.3.1.2 --- NorM efflux system --- p.21 / Chapter 1.4.2.4 --- 3rd generation cephalosporins --- p.22 / Chapter 1.4.2.4.1 --- Mosaic penA structure in reduced susceptible gonococcal strains --- p.22 / Chapter 1.4.2.4.2 --- Other mechanisms related to reduced susceptibility in gonococcal strains --- p.24 / Chapter 1.5 --- Application of molecular typing methods to study the epidemiology of N. gonorrhoeae --- p.24 / Chapter 1.5.1 --- Opa typing --- p.25 / Chapter 1.5.2 --- K gonorrhoeae Multi-Antigen Sequence Typing --- p.25 / Chapter 1.6 --- Project Objectives --- p.27 / Chapter CHAPTER 2. --- MATERIALS AND METHODS / Chapter 2.1 --- Collecting gonococcal strains --- p.29 / Chapter 2.2 --- Culturing of N. gonorrhoeae --- p.29 / Chapter 2.3 --- Identification --- p.29 / Chapter 2.3.1 --- Gram staining test --- p.30 / Chapter 2.3.2 --- Oxidase test --- p.31 / Chapter 2.3.3 --- Cabohydrate utilization test --- p.31 / Chapter 2.4 --- In-vitro antimicrobial susceptibility testing --- p.32 / Chapter 2.4.1 --- Preparation of cell cultures for MIC tests --- p.32 / Chapter 2.4.2 --- Preparation of antimicrobial agents for MIC tests --- p.32 / Chapter 2.4.3 --- Inoculum preparation and delivering --- p.33 / Chapter 2.5 --- Preparation of genomic DNA for detection of mutations --- p.34 / Chapter 2.6 --- Study of Resistant Mechanism against fluoroquinolone --- p.34 / Chapter 2.6.1 --- PGR detection of mutations in gyrA and parC genes --- p.35 / Chapter 2.6.2 --- Optimization of gyrA and parC genes PGR --- p.35 / Chapter 2.6.3 --- Detection of PGR products for gyrA and parC genes --- p.37 / Chapter 2.6.4 --- Purification of Amplified DNA products --- p.37 / Chapter 2.7 --- Tests of efflux inhibitor on N. gonorrhoeae --- p.38 / Chapter 2.7.1 --- Effect ofCCCP --- p.39 / Chapter 2.7.2 --- Effect of Reserpine --- p.39 / Chapter 2.8 --- Study of Resistant mechanism against β-lactams --- p.40 / Chapter 2.8.1. --- Detection for the presence of β-lactamase --- p.40 / Chapter 2.8.2 --- Mosaic penA patterns --- p.40 / Chapter 2.8.2.1 --- Detection of mutations in penA gene --- p.40 / Chapter 2.8.2.2 --- Optimization of penA gene PGR --- p.41 / Chapter 2.8.2.3 --- Detection of PGR products --- p.43 / Chapter 2.8.2.4 --- Purification of Amplified DNA products --- p.44 / Chapter 2.9 --- Detection of the presence of tetM determinant --- p.45 / Chapter 2.9.1 --- Optimization of tetM determinant PCRs --- p.46 / Chapter 2.9.2 --- Detection of PGR products --- p.47 / Chapter 2.10 --- Detection of different allele types in tbpB andpor genes --- p.48 / Chapter 2.10.1 --- Optimization of PGR for NG-MAST --- p.48 / Chapter 2.10.2 --- Detection of PCR products --- p.49 / Chapter 2.10.3 --- PCR product purification --- p.50 / Chapter 2.11 --- Sequencing of the PCR products --- p.51 / Chapter 2.12 --- Data Analysis --- p.52 / Chapter CHAPTER 3. --- RESULTS / Chapter 3.1 --- Gonococcal strains collected --- p.55 / Chapter 3.2 --- Identification of gonococcal strains --- p.55 / Chapter 3.3 --- MIC of Antimicrobial agents --- p.56 / Chapter 3.3.1 --- Interpretive Criteria --- p.56 / Chapter 3.3.2 --- Ciprofloxacin --- p.56 / Chapter 3.3.3 --- Penicillin --- p.57 / Chapter 3.3.4 --- Tetracycline --- p.57 / Chapter 3.3.5 --- Ceftriaxone --- p.58 / Chapter 3.3.6 --- Cefixime --- p.58 / Chapter 3.3.7 --- Cefotaxime --- p.58 / Chapter 3.3.8 --- Spectinomycin --- p.58 / Chapter 3.3.9 --- Levofloxacin --- p.59 / Chapter 3.3.10 --- Ceftibuten --- p.59 / Chapter 3.4 --- Result of PGR --- p.60 / Chapter 3.4.1 --- gyrA andparC genes --- p.60 / Chapter 3.4.2 --- penA gene --- p.61 / Chapter 3.4.3 --- tbpB and por genes --- p.62 / Chapter 3.4.4 --- tetM determinant --- p.62 / Chapter 3.5 --- β-lactamase --- p.63 / Chapter 3.6 --- Efflux pump inhibitor --- p.63 / Chapter 3.6.1 --- CCCP --- p.64 / Chapter 3.6.2 --- Reserpine --- p.64 / Chapter 3.7 --- Detection of Mutations --- p.66 / Chapter 3.7.1 --- gyrA and parC genes --- p.66 / Chapter 3.7.2 --- penA gene --- p.68 / Chapter 3.8 --- NG-MAST --- p.70 / Chapter 3.8.1 --- tbpB and por gene --- p.71 / Chapter 3.9 --- Porin mutation --- p.72 / Chapter CHAPTER 4. --- DISCUSSION / Chapter 4.1 --- Sampling --- p.74 / Chapter 4.2 --- Methodology --- p.75 / Chapter 4.3 --- MIC distribution of different antimicrobial agents --- p.76 / Chapter 4.4 --- Mechanisms of quinolone resistance --- p.78 / Chapter 4.4.1 --- Mutations at QRDRs --- p.78 / Chapter 4.4.2 --- Association of the number of mutations at parC gene with MIC levels against fluroquinolones --- p.80 / Chapter 4.5 --- Penicillin and Tetracycline Resistant Mechanisms --- p.81 / Chapter 4.6 --- Efflux system --- p.85 / Chapter 4.7 --- NG-MAST --- p.88 / Chapter 4.8 --- Mosaic penA pattern --- p.89 / Chapter 4.9 --- Management of gonorrhea --- p.90 / Chapter CHAPTER 5. --- CONCLUSIONS / REFERENCES