AntibiotisEnglish分析课件.ppt

Anti-bacteria Medicine Anti-bacteria medicine Antibiotics: The substance derived from fungi and bacteria which can selectively kill or inhibit bacteria growth Anti-bacteria medicine: Chemically synthesized medicine which can selectively kill or inhibit bacteria growth Antibacteria medicine Sulfonamide Quilonones others Antibiotics and drugs targeting nucleic acid biosynthesis and functions Antibiotics and drugs targeting nucleic acid biosynthesis and functions 1. Sulphonamides Trimethoprim (TMP) PABA false structure Inhibition of Dihydrofolate reductase Dihydrofolate ?? tetrahydrofolate 2. Quinolones Bacterial topoisomerase II- Gyrase Nalidixic acid Ofloxacin Ciprofloxacin 3. Rifampicin (from rifamycin) ? subunit of DNA-primed RNA polymease ! Rifampicin must be given by a “cocktail” of drugs. Problem of antibiotics which inhibit protein synthesis Antibiotics: From isolation of strain to clinical application Selection of a potential product 1、efficacy 2、metabolic characterization 3、toxicity and adverse effect 4、Potentiality of industrial production Antibiotics: from strain isolation to clinical application Semi-synthesis: the most popular approach of production Marketing potentiality Life-span of marketing and its impact Bacterial Resistance to Antibiotics ? Enzymes secreted (exo-enzyme) ? Enzymes not secreted (endo-enzymes) ? Deletion of target molecules ? Change in cell permeability ? Change in target molecule affinity ? Speed-up of synthesis and metabolism ? Others Mechanism of resistance Selection pressure ( not only in health institutions) Genetic recombination ( especially conjugation mediated by plasmid) Improper prescription of antibiotics Antibiotic prescription for non-bacterial infection Prophylaxis application of antibiotics Local application of antibiotics Over use of wide-spectrum antibiotics Long-term use of antibiotics Antibiotic abuse in ag