CELL WALL SYNTHESIS INHIBITORS Flashcards by Love Dog

T/F

→ bacterial cell wall composition:
o peptidoglycan
o glycan units joined by peptide cross-linkages

→ to be maximally effective, these inhibitors require actively proliferating microorganisms

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among the widely effective antibiotic and least toxic drug

A. PENICILLIN
B. CEPHALOSPORINS
C. B-LACTAMASE INHIBITORS
D. VANCOMYCIN
E. BACITRACIN
F. DAPTOMYCIN

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→ increased resistance has limited its use

A. PENICILLIN
B. CEPHALOSPORINS
C. B-LACTAMASE INHIBITORS
D. VANCOMYCIN
E. BACITRACIN
F. DAPTOMYCIN

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members of this group differ in the R substituent attached to 6-aminopenicillanic acid residue

o nature of this side chain affects the antimicrobial spectrum,
stability to gastric acid and susceptibility to bacterial degradative enzymes (B-Lactamase)

A. PENICILLIN
B. CEPHALOSPORINS
C. B-LACTAMASE INHIBITORS
D. VANCOMYCIN
E. BACITRACIN
F. DAPTOMYCIN

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interfere with bacterial cell wall synthesis (transpeptidation or cross-linkage)

A. PENICILLIN
B. CEPHALOSPORINS
C. B-LACTAMASE INHIBITORS
D. VANCOMYCIN
E. BACITRACIN
F. DAPTOMYCIN

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cell lysis or cell death

A. PENICILLIN
B. CEPHALOSPORINS
C. B-LACTAMASE INHIBITORS
D. VANCOMYCIN
E. BACITRACIN
F. DAPTOMYCIN

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T/ F

cell lysis through osmotic pressure or activation of autolysins

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cell lysis or cell death is related to:

o antibiotic size
o charge
o hydrophobicity

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effective only against rapidly growing organisms or those that synthesize peptidoglycan cell wall

A. PENICILLIN
B. CEPHALOSPORINS
C. B-LACTAMASE INHIBITORS
D. VANCOMYCIN
E. BACITRACIN
F. DAPTOMYCIN

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not effective in microorganisms devoid of peptidoglycan cell wall

A. PENICILLIN
B. CEPHALOSPORINS
C. B-LACTAMASE INHIBITORS
D. VANCOMYCIN
E. BACITRACIN
F. DAPTOMYCIN

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T/F

ANTIBACTERIAL SPECTRUM
is determined by the ability to cross bacterial peptidoglycan cell wall and to reach PBP in periplasmic space

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possess a cell wall easily traversed by penicillin
→ susceptible

A. Gram (+) Bacteria
B. Gram (-) Bacteria

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Thicker cell wall

A. Gram (+) Bacteria
B. Gram (-) Bacteria

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Can resist antibiotic

A. Gram (+) Bacteria
B. Gram (-) Bacteria

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possess outer lipopolysaccharide membrane that serves as a barrier to water-soluble penicillin

A. Gram (+) Bacteria
B. Gram (-) Bacteria

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may also posses proteins inserted along the lipopolysaccharide layer that act as water-channels, “porins”
to permit transmembrane entry

A. Gram (+) Bacteria
B. Gram (-) Bacteria

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exception:
o Pseudomonas lacks porins
making it resistant to many antimicrobials

A. Gram (+) Bacteria
B. Gram (-) Bacteria

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obtained from fermentation of mold Penicillium chrysogenum

A. NATURAL PENICILLIN
B. ANTISTAPHYLOCOCCAL PENICILLIN
C. EXTENDED SPECTRUM PENICILLIN
D. ANTIPSEUDOMONAL PENICILLINS
E. PENICILLIN & AMINOGLYCOSIDES

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PENICILLIN G (BENZYL-PENICILLIN)

A. NATURAL PENICILLIN
B. ANTISTAPHYLOCOCCAL PENICILLIN
C. EXTENDED SPECTRUM PENICILLIN
D. ANTIPSEUDOMONAL PENICILLINS
E. PENICILLIN & AMINOGLYCOSIDES

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cornerstone in treatment for infection of gram (+) & (-) cocci, (gram (+) bacilli, and spirochetes

A. PENICILLIN G (BENZYL-PENICILLIN)
B. PENICILLIN V

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can be inactivated by B-Lactamase (PCNases)

A. PENICILLIN G (BENZYL-PENICILLIN)
B. PENICILLIN V

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not used in treatment of bacteremia because it needs higher
minimum concentration to eliminate infection

A. PENICILLIN G (BENZYL-PENICILLIN)
B. PENICILLIN V

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more acid-stable; administered orally

A. PENICILLIN G (BENZYL-PENICILLIN)
B. PENICILLIN V

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effective against some anaerobic organisms

A. PENICILLIN G (BENZYL-PENICILLIN)
B. PENICILLIN V

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B-Lactamase (PCNase) resistant A. NATURAL PENICILLIN B. ANTISTAPHYLOCOCCAL PENICILLIN C. EXTENDED SPECTRUM PENICILLIN D. ANTIPSEUDOMONAL PENICILLINS E. PENICILLIN & AMINOGLYCOSIDES

used in treatment of infections caused by PCNase producing staphylococci A. NATURAL PENICILLIN B. ANTISTAPHYLOCOCCAL PENICILLIN C. EXTENDED SPECTRUM PENICILLIN D. ANTIPSEUDOMONAL PENICILLINS E. PENICILLIN & AMINOGLYCOSIDES

Methicillin is not used clinically due to toxicity and is only used to identify resistant strains of Staph. aureus (MRSA) A. NATURAL PENICILLIN B. ANTISTAPHYLOCOCCAL PENICILLIN C. EXTENDED SPECTRUM PENICILLIN D. ANTIPSEUDOMONAL PENICILLINS E. PENICILLIN & AMINOGLYCOSIDES

Ampicillin and Amoxicillin A. NATURAL PENICILLIN B. ANTISTAPHYLOCOCCAL PENICILLIN C. EXTENDED SPECTRUM PENICILLIN D. ANTIPSEUDOMONAL PENICILLINS E. PENICILLIN & AMINOGLYCOSIDES

→ have similar antibacterial spectrum with PCN-G → more effective against gram (-) bacilli A. NATURAL PENICILLIN B. ANTISTAPHYLOCOCCAL PENICILLIN C. EXTENDED SPECTRUM PENICILLIN D. ANTIPSEUDOMONAL PENICILLINS E. PENICILLIN & AMINOGLYCOSIDES

→ drug of choice for gram (+) bacillus L. monocytogenes → used in treatment of respiratory infection A. AMPICILLIN B. AMOXICILLIN

used by dentists for prophylaxis in patients with heart valve disease to undergo extensive oral surgery A. AMPICILLIN B. AMOXICILLIN

Piperacillin is the most potent A. NATURAL PENICILLIN B. ANTISTAPHYLOCOCCAL PENICILLIN C. EXTENDED SPECTRUM PENICILLIN D. ANTIPSEUDOMONAL PENICILLINS E. PENICILLIN & AMINOGLYCOSIDES

effective against many gram (-) bacilli but not Klebsiella (due to PCNase) A. NATURAL PENICILLIN B. ANTISTAPHYLOCOCCAL PENICILLIN C. EXTENDED SPECTRUM PENICILLIN D. ANTIPSEUDOMONAL PENICILLINS E. PENICILLIN & AMINOGLYCOSIDES

Clavulanic Acid + Ticarcillin A. NATURAL PENICILLIN B. ANTISTAPHYLOCOCCAL PENICILLIN C. EXTENDED SPECTRUM PENICILLIN D. ANTIPSEUDOMONAL PENICILLINS E. PENICILLIN & AMINOGLYCOSIDES

Tazobactam + Piperacillin A. NATURAL PENICILLIN B. ANTISTAPHYLOCOCCAL PENICILLIN C. EXTENDED SPECTRUM PENICILLIN D. ANTIPSEUDOMONAL PENICILLINS E. PENICILLIN & AMINOGLYCOSIDES

have a synergistic relationship because cell wall inhibitors alter the permeability of bacterial cells which facilitate entry of other antibiotics to intracellular target sites → enhanced antimicrobial activity A. NATURAL PENICILLIN B. ANTISTAPHYLOCOCCAL PENICILLIN C. EXTENDED SPECTRUM PENICILLIN D. ANTIPSEUDOMONAL PENICILLINS E. PENICILLIN & AMINOGLYCOSIDES

combination of both is used clinically but should never be in one infusion fluid o aminoglycoside is positively charged while PCN is negatively charged A. NATURAL PENICILLIN B. ANTISTAPHYLOCOCCAL PENICILLIN C. EXTENDED SPECTRUM PENICILLIN D. ANTIPSEUDOMONAL PENICILLINS E. PENICILLIN & AMINOGLYCOSIDES

→ lacks peptidoglycan cell wall A. Natural Resistance B. Acquired Resistance

cell wall that is impermeable to PCN A. Natural Resistance B. Acquired Resistance

through plasmid transfer which encodes resistance A. Natural Resistance B. Acquired Resistance

PROPERTIES OF PLASMID-RESISTANCE BACTERIA [3]

BETA-LACTAMASE ACTIVITY DECREASED PERMEABILITY OF OUTER MEMBRANE TO THE ANTIBIOTIC ALTERED PBPs

these enzymes hydrolyze cyclic amide bond of B-Lactam ring which results in loss of bactericidal activity A. BETA-LACTAMASE ACTIVITY B. DECREASED PERMEABILITY OF OUTER MEMBRANE TO THE ANTIBIOTIC C. ALTERED PBPs

either naturally occurring or acquired by the transfer of plasmids A. BETA-LACTAMASE ACTIVITY B. DECREASED PERMEABILITY OF OUTER MEMBRANE TO THE ANTIBIOTIC C. ALTERED PBPs

prevents it from reaching target protein PBP A. BETA-LACTAMASE ACTIVITY B. DECREASED PERMEABILITY OF OUTER MEMBRANE TO THE ANTIBIOTIC C. ALTERED PBPs

have a lower affinity for B-Lactam antibiotics and will need unattainable concentration of antibiotic to take effect (MRSA) A. BETA-LACTAMASE ACTIVITY B. DECREASED PERMEABILITY OF OUTER MEMBRANE TO THE ANTIBIOTIC C. ALTERED PBPs

secretes B-Lactamase extracellularly A. Gram (+) Bacteria B. Gram (-) Bacteria

confine B-Lactamase within periplasmic space A. Gram (+) Bacteria B. Gram (-) Bacteria

T/ f IV or IM for all antipseudomonal PCN (Ticarcillin, Carbenicillin, Piperacillin)

T/ f Oral for Pen V; Amoxicillin

T/ F Procaine Pen-G and Benzathine Pen-G given IM

T/ F ABSORPTION Amoxicillin is almost completely absorbed; not appropriate for treatment of Shigella or Salmonella-derived enteritis (does not reach intestinal crypts)

T/F Absorption Amoxicillin is almost completely absorbed; not appropriate for treatment of Shigella or Salmonella-derived enteritis (does not reach intestinal crypts)

T/ F DISTRIBUTION all penicillin cross placental barrier and are non-teratogenic

T/ F Penicillin is excreted through kidney or breast milk

T/ f PENICILLIN Adverse reactions: Hypersensitivity [maculopapular rash, angioedema, anaphylaxis]

T/ f PENICILLIN Adverse reactions: Diarrhea, Nephritis, Neurotoxicity, Hematologic Toxicities

decreased coagulation caused by anti-pseudomonal penicillin and Pen-G; eosinophilia

Hematologic Toxicities

are B-Lactam antibiotics that are closely related as to structure and function to penicillin A. PENICILLIN B. CEPHALOSPORINS C. B-LACTAMASE INHIBITORS D. VANCOMYCIN E. BACITRACIN F. DAPTOMYCIN

→ most are produced semi-synthetically → same mode of action with penicillin and are affected by the same resistance mechanism but tend to be more resistant to certain B-Lactamases A. PENICILLIN B. CEPHALOSPORINS C. B-LACTAMASE INHIBITORS D. VANCOMYCIN E. BACITRACIN F. DAPTOMYCIN

classified as first, second, third, or fourth generation based on their susceptibility patterns and resistance to B-Lactamases A. PENICILLIN B. CEPHALOSPORINS C. B-LACTAMASE INHIBITORS D. VANCOMYCIN E. BACITRACIN F. DAPTOMYCIN

ineffective against MRSA, L. monocytogenes, Clostridium difficile, and Enterococci A. PENICILLIN B. CEPHALOSPORINS C. B-LACTAMASE INHIBITORS D. VANCOMYCIN E. BACITRACIN F. DAPTOMYCIN

act as Pen-G substitute; resistant to staph penicillinase A. First Generation B. Second Generation C. Third Generation D. Fourth Generation

has activity against P. mirabilis, E. coli, K. pneumoniae A. First Generation B. Second Generation C. Third Generation D. Fourth Generation

have greater activity against gram (-) organisms (ex.: H. influenza, Enterobacter aerogenes, Neisseria species) A. First Generation B. Second Generation C. Third Generation D. Fourth Generation

have a weaker action on gram (+) microorganisms A. First Generation B. Second Generation C. Third Generation D. Fourth Generation

have greater activity against gram (-) bacilli and most enteric organisms plus Serratia marcescens A. First Generation B. Second Generation C. Third Generation D. Fourth Generation

Ceftriaxone or Cefotaxime is the drug of choice for meningitis A. First Generation B. Second Generation C. Third Generation D. Fourth Generation

Ceftazidime has activity against P. aeruginosa A. First Generation B. Second Generation C. Third Generation D. Fourth Generation

Cefepime A. First Generation B. Second Generation C. Third Generation D. Fourth Generation

administered parenterally A. First Generation B. Second Generation C. Third Generation D. Fourth Generation

has a wide antibacterial spectrum of activity; active against streptococci and staphylococci A. First Generation B. Second Generation C. Third Generation D. Fourth Generation

effective against aerobic gram (-) organisms (ex.: K. pneumoniae, Enterobacter, P. mirabilis, E. coli, P. aeruginosa) A. First Generation B. Second Generation C. Third Generation D. Fourth Generation

RESISTANCE → same as with penicillin but not susceptible to hydrolysis by Staph penicillinase → susceptible to extended-spectrum B-Lactamase A. PENICILLIN B. CEPHALOSPORINS C. B-LACTAMASE INHIBITORS D. VANCOMYCIN E. BACITRACIN F. DAPTOMYCIN

→ administered through IV or IM → poor oral absorption except for certain drugs (refer to summary table) → all are well-distributed in body fluids → in the CSF, adequate therapeutic levels are achieved with third generation regardless of inflammation o Ceftriaxone or Cefotaxime are effective in treatment of neonatal or childhood meningitis A. PENICILLIN B. CEPHALOSPORINS C. B-LACTAMASE INHIBITORS D. VANCOMYCIN E. BACITRACIN F. DAPTOMYCIN

Cefazolin is used as a single-dose prophylaxis prior to surgery due to its 1.8 hours half-life and is effective against PCNase producing S. aureus o also useful in orthopedic surgery because it can penetrate bone o all cephalosporins can cross the placenta A. PENICILLIN B. CEPHALOSPORINS C. B-LACTAMASE INHIBITORS D. VANCOMYCIN E. BACITRACIN F. DAPTOMYCIN

T/F allergic manifestations o if allergic to penicillin, avoid cephalosporins

mechanism of action: o hydrolysis of B-Lactam ring by enzymatic cleave with B-Lactamase or by an acid A. PENICILLIN B. CEPHALOSPORINS C. B-LACTAMASE INHIBITORS D. VANCOMYCIN E. BACITRACIN F. DAPTOMYCIN

Clavulanic Acid, Sulbactam, Tazobactam o contain B-Lactam ring o bind to and inactivate B-Lactamases o protect the antibiotic that are the normal substrates for enzymes A. PENICILLIN B. CEPHALOSPORINS C. B-LACTAMASE INHIBITORS D. VANCOMYCIN E. BACITRACIN F. DAPTOMYCIN

→ by themselves, do not have significant antibacterial activity → must be used in combination with B-Lactamase sensitive antibiotic (ex.: Clavulanic Acid + Amoxicillin = for B-Lactamase producing E. coli) A. PENICILLIN B. CEPHALOSPORINS C. B-LACTAMASE INHIBITORS D. VANCOMYCIN E. BACITRACIN F. DAPTOMYCIN

→ tricyclic glycopeptide → effective against multiple drug resistant microorganisms → MRSA and enterococci A. PENICILLIN B. CEPHALOSPORINS C. B-LACTAMASE INHIBITORS D. VANCOMYCIN E. BACITRACIN F. DAPTOMYCIN

MODE OF ACTION → inhibit synthesis of bacterial cell wall phospholipids and peptide-glycan polymerization; thus, weaken cell wall and damage underlying cell membrane A. PENICILLIN B. CEPHALOSPORINS C. B-LACTAMASE INHIBITORS D. VANCOMYCIN E. BACITRACIN F. DAPTOMYCIN

ANTIBACTERIAL SPECTRUM → effective primarily against gram (+) organisms → lifesaving in treatment of MRSA, MRSE, and enterococcal infection A. PENICILLIN B. CEPHALOSPORINS C. B-LACTAMASE INHIBITORS D. VANCOMYCIN E. BACITRACIN F. DAPTOMYCIN

to prevent emergence of vancomycin resistant organisms, vancomycin use is restricted to: o serious infection caused by B-lactam resistant gram (+) organisms o patients with gram (+) infection and allergic to B-lactams A. PENICILLIN B. CEPHALOSPORINS C. B-LACTAMASE INHIBITORS D. VANCOMYCIN E. BACITRACIN F. DAPTOMYCIN

limited for treatment of antibiotic-associated colitis due to C. difficile or Staphylococci A. Oral Vancomycin B. Vancomycin C. Vancomycin + Aminoglycoside

used in patients with prosthetic heart valves and in patients undergoing implantation of prosthetic A. Oral Vancomycin B. Vancomycin C. Vancomycin + Aminoglycoside

used in treatment of enterococcal endocarditis A. Oral Vancomycin B. Vancomycin C. Vancomycin + Aminoglycoside

Vancomycin-resistant organisms may be treated with the ff?

Daptomycin Qunipristin/Dalfopristin & Linezolid

a cyclic lipopeptide antibiotic A. Daptomycin B. Qunipristin/Dalfopristin & Linezolid

Daptomycin

protein synthesis inhibitors A. Daptomycin B. Qunipristin/Dalfopristin & Linezolid

RESISTANCE → due to: o plasmid-mediated changes in permeability to the drug o decrease binding of vancomycin to receptor molecules A. PENICILLIN B. CEPHALOSPORINS C. B-LACTAMASE INHIBITORS D. VANCOMYCIN E. BACITRACIN F. DAPTOMYCIN

→ mixture of polypeptides that inhibit cell wall synthesis → active against wide variety of gram (+) organisms → use is restricted to topical application (due to nephrotoxicity) A. PENICILLIN B. CEPHALOSPORINS C. B-LACTAMASE INHIBITORS D. VANCOMYCIN E. BACITRACIN F. DAPTOMYCIN