Deliberations on the impact of antibiotic contamination on dissemination of antibiotic resistance genes in aquatic environments

............................................................................. V Summary in Swedish (Populärvetenskaplig sammanfattning)............ VII List of papers....................................................................... IX Abbreviations....................................................................... X History of antibiotics and the emergence of resistance........................... 1 Horizontal gene transfer and gene transfer elements............................. 3 Transformation......................................................................................... 3 Transduction............................................................................................. 4 Conjugation.............................................................................................. 5 Gene transfer elements............................................................................. 6 Plasmids................................................................................................... 6 Transposable elements............................................................................. 7 Integrative conjugative elements.............................................................. 7 Integrons................................................................................................... 8 Antibiotics and antibiotic resistance genes.............................................. 11 Sulphonamides and trimethoprims...................................................... 11 History and mechanism of action of sulphonamide and trimethoprim antibiotics....................................................................... 11 Resistance mechanisms and determinants........................................... 12 Tetracyclines........................................................................................... 13 History and mechanism of action of tetracycline antibiotics............... 13 Resistance mechanisms and determinants........................................... 14 Glycopeptides.......................................................................................... 16 History and mechanism of action of glycopeptide antibiotics............. 16 Resistance mechanisms and determinants........................................... 16 Quinolones............................................................................................... 18 History and mechanism of action of quinolone antibiotics.................. 18 Resistance mechanisms and determinants........................................... 20 Macrolides............................................................................................... 21 History and mechanism of action of macrolide antibiotics................. 21 Resistance mechanisms and determinants........................................... 22 Antibiotics and antibiotic resistance genes in an environmental context.......................................................................................................... 24 Origins and roles of antibiotics and antibiotic resistance genes in the environment........................................................................................ 24 Environmental dissemination and prevalence of antibiotics and resistance genes........................................................................................ 25 Methodology................................................................................................ 28 Mass spectrometry................................................................................. 28 Principles of mass spectrometry and accompanying preparatory methods............................................................................. 28 Applications of LC-MS........................................................................ 30 Real-time PCR........................................................................................ 30 The polymerase chain reaction............................................................. 30 PCR monitoring in real-time................................................................ 31 Detection formats used in real-time PCR............................................. 31 Quantification with real-time PCR....................................................... 32