MMSC 438 Final Exam Set Q&A Correctly Answered

MMSC438 Final Exam Set Q&A Correctly Answered 1. Antibiotic vs. antimicrobial - ANSWER-antibiotic: substance produced by a MO that inhibits the growth or kills other MOs -antimicrobial agent: substance produced by MOs or synthetic means that inhibits the growth or kills MOs (antibacterial, antiviral, antifungal, antiparasitic) 2. Properties of antimicrobial agent - ANSWER-selectively toxic: active against targeted causative agent but not harmful to patient (limited side effects, no allergies, low toxicity, low impact on normal biota) -able to penetrate/distribute to infected tissues -active concentrations of drug are achieved rapidly in body (active in blood, body fluids and exudate) -organisms do not develop resistance -cost effective 3. Cell wall synthesis inhibitors – ANSWER -beta lactam: penicillin, cephalosporin, carbapenem, monobactam -glycopeptide: vancomycin, teicoplanin 4. Beta lactam mechanism of action – ANSWER irreversible binding to enzymes responsible for mature peptidoglycan molecule -transpeptidase/transglycolase (AKA penicillin binding proteins, PBPs): enzymes responsible for incorporation f glucans and AAs into peptidoglycan 5. Penicillins (beta-lactam) - ANSWER-the "-cillins" -penicillin G and V, ampicillin, amoxicillin, methicillin, ticarcillin -beta lactam ring present 6. Cephalosporin generations (beta-lactam) - ANSWER-the "cephs/cefs" -1st gen: mostly active against GP; ex: cephalexin, cephalothin -2nd gen: active against GP and GN (including H. influenzae, Enterobacter and some Neisseria); ex: cefoxitin, cefotetan *-3rd gen: active against GN and can penetrate into CSF; ex: cefotaxime, ceftriaxone, ceftazidime* -4th gen: active against more GN, many GP and has b-lactamase stability; ex: cefepime -5th gen: like 4th gen but more GP coverage and b-lactamase stability, active against MRSA; ex: ceftaroline 7. Monobactams (beta-lactam) - ANSWER-ex: aztreonam 8. Carbapenems (beta-lactam) - ANSWER-the "penems" -ex: ertapenem, imipenem, meropenem 9. Glycopeptides – ANSWER inhibit peptidoglycan synthesis by binding to the 2 terminal d-alanine on the pentapeptide chain, which blocks the cross-linking 10, Vanocmycin and teicoplanin - ANSWER-active against GP only (ex. MRSA and C. dif) -too large to enter GN outer membrane 11. Plasma membrane damage (antimicrobial mechanisms of action) – ANSWER polypeptide family: polymyxin and colistin (break apart GN outer membranes) 12. Protein synthesis inhibitors - ANSWER-tetracycline -macrolide -aminoglycoside -chloramphenicol -lincosaminde -ketolide