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