Concept 3:MBC and MIC Minimal bactericidal concentration (MBC): The lowest concentration of antibiotic required to kill a particular bacterium. Minimal inhibitory concentration(MIC) The lowest concentration of antimicrobial agents that prevents visible growth in 18-24 hours incubation
Concept 3: MBC and MIC Minimal bactericidal concentration (MBC): The lowest concentration of antibiotic required to kill a particular bacterium. Minimal inhibitory concentration (MIC) The lowest concentration of antimicrobial agents that prevents visible growth in 18-24 hours incubation
Concept 4 chemotherapy index Chemotherapy index (Cl) To evaluate the safety of chemotherapeutic drugs ·LDs0/ED50
Concept 4 chemotherapy index Chemotherapy index (CI) • To evaluate the safety of chemotherapeutic drugs • LD50 /ED50
inoculum of test bacteria growth medium+ antibiotic antibiotic 16 8 4 2 0.5 0.25 0.12mg concentration overnight incubation read MIC MIC of antibiotic =1mg/ subculture to drug-free 16 8 4 2 0.5 0.25 0.12mg/1 agar overnight incubation MIC of read MBC antibiotic =2mg/ Fig.30.35 More precise measures of the amount of antibiotic the standard method as outlined in this illustration,the MIC result is required to inhibit and kill a bacterial population can be estimated available after 24 hours and the MBC result after 48 hours.A by establishing the minimum inihibitory concentration(MIC)and number of variables such as the inoculum size,the growth medium minimum bactericidal concentration(MBC)of the antibiotic.Using and the interpretation of the results affect the results of MIC tests
Concept 5:Post-antibiotic effect The antibiotic inhibits microbial multiplication beyond the time when the MIC is reached in plasma. -Aminoglycosides(氨基糖苷类) -Macrolides(大环内酯类) Allows reduction in dosing schedule (once daily) Why PAE？Home work,then discuss it at next class
Concept 5: Post-antibiotic effect • The antibiotic inhibits microbial multiplication beyond the time when the MIC is reached in plasma. – Aminoglycosides （氨基糖苷类） – Macrolides （大环内酯类） • Allows reduction in dosing schedule (once daily) • Why PAE? Home work, then discuss it at next class
Mechanisms of antimicrobial drugs
Mechanisms of antimicrobial drugs