antibiotics

Inhibition of uncoating

Amantadine Timantadine

Broad spectrum

Cefotaxime Cefazolin Cefuroxime Cephalexin Ceftriaxone Cefixime

Why are penicillins more effective against Gram positive bacteria? A. Gram positive bacteria have a thin layer of peptidoglycan B. Gram positive bacteria have a thick layer of peptidoglycan C. Gram positive bacteria have an outer membrane D. Gram positive bacteria lack an outer membrane

B. Gram positive bacteria have a thick layer of peptidoglycan D. Gram positive bacteria lack an outer membrane

Bacitracin

Effective against Gram-positive bacteria

Narrow spectrum antibiotics

Effective against specific bacteria

4th step antibiotic resistance

Efflux of antibiotic Drug is rapidly removed from the cell before it can have an effect

2nd step antibiotic resistance

Inactivation by enzymes Beta-lactamase

Rifamycins

Inhibit synthesis of RNA

Sulfonamides

Inhibition of folic acid synthesis Structural analogs Bacteriostatic

Tetracycline

Interfere with attachment of tRNAto prevent addition of new amino acids to the polypeptide chain Effective against Gram positive and Gram negative bacteria

Broth dilution test

MIC -minimum concentration that inhibits microbial growth MBC -minimum concentration that kills all bacteria

broad spectrum bacteria

antibiotic that acts against a wide range of disease-causing bacteria

Quinolones and fluoroquinolones

inhibit DNA gyrase

Bacteriostatic

inhibit microbial growth when present

Aminoglycosides

inhibition of protein synthesis Alter the shape of the 30S subunit so mRNA is not translated correctly Streptomycin Neomycin Gentamicin

Chloramphenicol

inhibitor of protein synthesis Inhibits formation of peptide bonds (50S ribosomal subunit) Broad spectrum

Bactericidal

kills microbes directly

Beta-lactams

penicillin binding protein

Antibiotic

substance produced by a microorganism in small quantities that acts to inhibit other microbes

Antimicrobial drug

synthetically produced compound with antimicrobial activities

Inhibition of cell wall synthesis

β-lactams Penicillins Cephalosporins Bacitracin Vancomycin Affect peptidoglycan synthesis

Agricultural use of antibiotics

70% of antibiotics used in the United States Can contribute to rise of antimicrobial resistance Antibiotics kill susceptible bacteria Naturally resistant bacteria survive and reproduce (passing on resistance) Resistant bacteria repopulate animal

Triple antibiotic ointment contains polymyxin B, neomycin, and bacitracin. What three antimicrobial actions are represented in this ointment? A. Inhibition of cell wall synthesis B. Inhbition of protein synthesis C. Inhibition of nucleic acid synthesis D. Injury to plasma membrane E. Inhibition of essential metabolite synthesis

A. Inhibition of cell wall synthesis B. Inhbition of protein synthesis D. Injury to plasma membrane

3rd step antibiotic resistance

Alteration of target molecule Aminoglycoside Tetracycline Macrolides Methicillin

Peptidoglycan synthesis

Affects actively growing cells Low toxicity for host More effective against Gram positive bacteria

Interferons

Alpha interferon

1st step antibiotic resistance

Blocking entry Enzymes in periplasmic space Alteration of porins

Injury to plasma membrane

Changes permeability Loss of cellular contents

Antibiotics that inhibit protein synthesis have side effects... A. ...because all cells have proteins B. ..only in the few cells that make proteins C. ..because eukaryotic cells have 80S ribosomes D. ...at the 70S ribosomes in eukaryotic cells E. None of the above. These drugs have no side effects.

D. ...at the 70S ribosomes in eukaryotic cells

antiviral drugs

Drugs that act, are effective, or are directed against viruses.

Inhibition of entry and fusion

Maraviroc Enfuvirtide

vancomycin

Narrow spectrum Treatment of MRSA

Semisynthetic penicillins

Oxacillin Ampicillin

Protease inhibitors

Saquinavir Telaprvir

Inhibition of essential metabolite synthesis

Sulfonamides Sulfmethoxazole Trimethoprim

natural penicillin

Susceptible to bacterial β-lactamases Narrow spectrum of activity

Antifungal drugs

Target the plasma membrane of fungi

Neuraminidase inhibitors

Zanamivir

Selective toxicity

the property of some antimicrobial agents to be toxic for a microorganism and nontoxic for the host