Antibacterial Agents

A chemical substance that can inhibit the growth of or kill bacteria

What is an antibiotic?

An agent used to kill all types of microorganisms

What is an antimicrobial?

Only targets small/ limited # of bacteria

What is narrow spectrum?

Effective against wide array of bacteria

What is broad spectrum antibiotics?

Less resistance - only tx its specific organism

What are benefits of narrow spectrum?

You have to ID what you are treating

What are cons of narrow spectrum?

Less of an ID needed to tx

What are Pros of broad spectrum?

Developing resistance

Disruption of normal biome

What are cons of broad spectrum?

Kills

Inhibits growth of

A bactericidal ___ bacteria, a bacteriostatic ____ bacteria?

Bacteriostatic - dont have an immune system to kill them

You should not use ____ antibiotics w/ immunocompramized people?

Selective toxicity - not target host cells

What is the goal of making an antibiotic?

Selective toxicity

Soluble in body fluids

Toxicity not easily altered

Nonallergenic

Stability

Bacterial resistance not easily acquired

Reasonable cost

List the things effective antibiotics will have?

NAG and NAM - made in cytoplasm

AA added to side chains on them

-Units transported across cell membrane

-Transpeptidase will cross link AA side chains

Explain the steps of bacterial cell wall synthesis?

B-lactams

Vancomycin

Baciracin

What are the three cell wall synthesis inhibitors?

Binding and blocking transpeptidase - preventing cross-linking of peptidoglycan layers (cell bursts can't osmoregulate)

What are the pharmacodynamics of b-lactam antibiotics?

Gram + and -

b-lactam is effective against what bacteria?

Blocking transglycosylation and transpeptidation steps of peptidoglycan synthesis (no removal of Ala side chain no linking)

What is the pharmacodynamics of Vancomycin?

MRSA

What is Vancomycin used for?

Prevents dephosphorylation of bactoprenol resulting in no transportation of NAG-NAM complexes

What is the pharmacodynamics of Bacitracin?

Cationic detergent disrupting membrane structures

What are the pharmacodynamics of Polymyxins?

Irreversible binding of 30S subunits and blocking formation of the initiation complex.

-Missreading/ premature release of mRNA - stops synthesis

What is the pharmacodynamics of Aminoglycosides?

Binds to the 30S subunit and prevents attachment of aminoacyl-tRNA to the complex

What are pharmacodynamics of Tetracyclines?

Binds to 50S subunit, inhibits peptides transferase

What are the phamacodynamics of amphenicols?

Binds to 50s subunit locking formation of initiation complex and translocation

What are the pharmacodynamics of Macrolides?

Binds to 50S subunit and disrupts protein synthesis

What are the pharmacodynamics of lincosamides?

Bind to different sites on 50s ribosomal subunit, inhibit protein synthesis at different steps

What are the pharmacodynamics of streptogramins?

Inhibit DNA gyros and topoisomerase 4 prevent chromosome from unwinding and duplicating

What are the pharmacodynamics of quinolones/floroquinolones?

Inhibit DNA-depended RNA polymerase - preventing transcription of mRNA

What are the pharmacodynamics of Rifamycins?

Pro-drug - covalently binds to DNA resulting in it breaking

What are pharmacodynamics of metronidazole?

Interferes w/ folic acid synthesis needed for DNA synthesis (antimetabolites)

What are pharmacodynamics of sulfonamides and diaminopyrimidines?