抗生素PPT课件（英文精品）Simple Antibiotic .ppt

Simple Antibiotic Guide How do antibiotics kill ? How do antibiotics kill ? Interfere with critical components of the bacterial life cycle Lack of toxicity is dependent upon the lack of activity on OUR life cycle (otherwise the drugs are known as chemotheraputic agents or poisons) How do β-lactams kill ? How do β-lactams kill ? Inhibit the production of bacterial cell wall Therefore they don’t kill our cells, but they don’t kill mycoplasma or chlamydia either (they lack a cell wall….remember ?) What about other antibiotics? Aminoglycosides - Macrolides –Tetracyclines- Clindamycin All inhibit protein synthesis via ribosomes Quinolones block DNA synthesis Daptomycin blocks AA transport What is Synergy and when do you want it? Additive is: 2 + 2 = 4 Synergy is: 2 + 2 = 7 Example of synergy: cell wall active drug + protein inhibitor How do β-lactams kill the enterococcus? How do β-lactams kill the enterococcus? Trick question- it doesn’t . Only inhibits their growth……………… Which brings us to the issue of Cidal vs Static antibiotics (and synergy also) WHAT is Inhibitory (static)? In a test tube there is no change over time What is CIDAL ? DEAD ? ALMOST DEAD ? MOSTLY DEAD? EVENTUALY DEAD ? What is CIDAL ? In 24 hours 99.9% of the buggers are DEAD So is it ever important to use a cidal antibiotic? So is it ever important to use a cidal antibiotic? Yes - for Endocarditis always always always (is that clear???) No - for almost everything else Maybe (for those of you that can’t decide)- for neutropenic patients in treatment of meningitis for osteomyelitis CIDAL or STATIC ??? Beta lactams CIDAL or STATIC ??? Beta lactams CIDAL **** Aminoglycosides CIDAL or STATIC ??? Beta lactams CIDAL Aminoglycosides CIDAL too Quinolones CIDAL or STATIC ??? Beta lactams CIDAL Aminoglycosides CIDAL Quinolones CIDAL Tetracyclines BACTERIOCIDAL or STATIC ??? Beta lactams