beta lactam antibiotics peniciillin,ampicillin, cephalosporin

Question 1

bacterial resistamce to penicillin and other beta lactams

Answer 1

release of penicillinase by bacteria
penicillin tolerant enzyme having low affinity for beta lactams eg MRSA methicillin resistant staph aurues
porin channels in gram negative bacteria permeable to ampicillin
porin channel removed resistance developed

Question 2

classification of cephalosporins

Answer 2

FIRST GEN :parentral cefazolin
oral ; cephalexin, cephadroxil, cepharadine

SECOND GEN:parentral cefuroxime
oral
cefuroxime axetil, cefaclor

THIRD GEN: parentral; ceftriaxzone 
                         ceftizoxime ceftazidine
oral ceftriaxone axetil
ceftibuten 
 FOURT Gen
only parentral cefipime 

FOURTH GEN: