April 3, 2007

April 3, 2007  Announcement o Case 4 is due in a week’s time o Not the same extent as most of the other cases Antimicrobials  Reviewing the whole pathophysicological basis of antimicrobials  Terms and Definitions o Chemotherapy  Any drug that’s going to get rid of the organism o Antibiotic  Anything that will inhibit the growth or kill the microorganisms  Antimicrobial Spectrum o Narrow spectrum – eg. Penicillin o Broad spectrum – most freq. used b/c kills off so many species  Most likely to cause superinfection  Concentration and Time-Dependent Effects o MIC  Test that determines the in dose that will kill off the species  Used to determine which species are susceptible to the drug and which are not o CDKR  If give more will kill more species  True with a great majority of antibiotics but NOT with penicillin o PAE  Drug has an effect against the organism even after drug removed  Prolonged effect o Ideal drug is one that has CDKR and PAE – b/c this is drug that only have to give once a day and give in large dose and is safe  Microbial Sensitivity o All are basically similar o Take a pool of bacteria o Add different antibiotics o Can gather a faint circle around it o Determines which Ab has the strongest effect for that species o Etest – taking an agar plate and instead of the plate with different drug, trying to find the MIC of one drug  Uses different concentrations  Will see o Peak conc. Has to be 2-4x – to get right conc.  Microbial Resistance o (1 in 1012) should be (1 in 1012) o Mutations occur as they are dividing o If give drug at point where already developed

o Mutations occur if:  If don’t have strong enough dose of Ab - don’t stop Ab if your child is feeling better  On a course of Ab for a very long time • Longer the Ab is around the longer the microbe has a chance to mutate o Transferable resistance  One microbe can bass on resistance to another  Bacteria can serve has reservoir for this resistance factor 