Chapter 10 Flashcards
Inhibition of Cell Wall Synthesis
Simplest beta-lactams are effective against what?
aerobic Gram Negative
Ideal Antimicrobial Agent is
readily availale
inexpensive
cheically stable
easily administered
nontixic and nonalergenic
selectively toxic against wide range of pathogens
Inhibition of Protein Synthesis
Streptomycin
Erythromycin
Tetracycline
Chloramphenicol
are drugs that inhibit protein synthesis in what karyotic ribosomes?
Prokaryotic ribosomes which are 70s (30s and 50s)
Mitochondria of animals and humans contain 70s ribosomes
Eukaryotic ribosomes are 80s (40s and 60s)
Disruption of Cytoplasmic Membranes
-humans somewhat susceptible because?
cholesterol similar to ergosterol
Spectrum of Action acts in two ways what are those?
narrow and broad spectrum
Disruptioin to Cytoplasmic Membrane
Some drugs act against cytoplasmic membranes, what are those drugs?
some parasitic drugs
Disruption of Cyoplasmic Membranes
What drugs from a channel through the cytoplasmic membrane and damage its integrity
Amphotericin B
nystatin
Antimicrobial drugs constitute largest….
Antimicrobial drugs constitute largest number of diversity of antimicrobial agents
Inhibition of Nucleic Acid Sythesis
what drug acts against prokaryotic DNA gyrase (releaves stress as DNA is unwound)
Quinolones and fluroquinololnes
Inhibition of Nucleic Acid Synthesis
Nucleotide analogs interfere with the function of?
nucleic acids
Mechanisms of resistance
Produce enzyme that destoys or deactivates drug such as beta-lactamase, how does that happen?
If our body makes Beta-Lactam the bacteria will then make the enzyme Beta-Lactamase to hinder the drugs use aginst it
NOW we make Clavulanic acid…it is belived bacteria will soon be reistant to that. bacteria makes the ristant faster than we can build against it
Inhibition of Cell Wall Synthesis
Beta-lactams weaken what part of the bacteria?
Baceria’s cell wall which evenutally lyse
Coined the term ‘antibiotics’ antimicrobial agents produced naturally by organisms
Selman Waksman
Inhibition of Nucleic Acid Sythesis
Nucleotide Analogs are most often used against what?
what drug inhibits RNA and DNA replication?
against viruses
Ribavirin
How do bacteria become resistanc to anitbiotics?
new mutations in chromosonal genes
Acquisition of R-plasmids via tranformation transduction and conjugation.
Chemically altered antibiotics that are more effective than naturally occurring ones b/c they have a larger spectrum of action
Semisynthetic
Disruption of Cytoplasmic Membrane
why are some Bacterial not susceptible to Amphotercin B?
because they lack sterols
Inhibition of Protein Synthesis
blocks met-tRNA docking
Streptomycin
Inhibition of Nucleic Acid Sythesis
inhibitors of RNA polymerase during transcription affect acterial RNApoly, what drugs?
Actinomycin and rifampicin
Inhibition of Nucleic Acid Sythesis
Nucleotide analongs distort shapes of nucleic acids molecules and also prevent what other 3 processes?
replication, Transcription and Translation
Antimicrobial that are completely synthesized in a lab
Synthetics
where does the plate clear
3.1 first clear plate (MBC)
pour on plate for test
Few drugs to treat….
eukaryotic infections
Routes of Administration of antibiotic
Topical application - of drug for external infections
Oral route - requires no needles and is self adminstered
Intramuscular adminstration - delivers drug via needle into muscle
Intravenous adminstration - delivers drug directly to bloodstream
(the blood brain barrier (BBB) is a difficult one to cross for brain infections
Braod Spectrum effective against many organisms
May allow for?
Can kill what time of bacteria in our body?
may allow for secondary or superinfections to develop
Killing of normal flora reduces microbial anagonism
Inhibition of Protein Synthesis
blocks tRNA docking site (A-site)
Tetracycline
Inhibition of Cell Wall Synthesis
Penicillin, amoxicillin, ampicillin, methicillin are?
Beta-lactams
Inhibition of Metabolic Pathways
what agents can be effective when metabolic processes of pathogen and host differ
Antimetabolic agents
Discovered sulfanilamide, the first commercially available antibiotic
Gerhard Dmagk
Inhibition of Metabolic Pathways
What drugs prevent prevent viral upcoating
Amantadine, rimantadine, and weak organic bases
Key is selective…
toxicity
Disruptioin to Cytoplasmic Membrane
what drug binds to LPS and disrupts cytoplasmic membranes of gram negative and is toxic to human kidneys?
Polymyxin
Safety and Side Effects
Toxicity causes many adverse reactions poorly understood
Drugs can be toxic to what orgains?
Tetracyclines can become incorporated into what parts of are body? effects pregnant woman too.
Kidneys, Liver, or Nerves
Tetracyclines can become incorportated into bones and teeth of fetus, distroys gums in teeth and causes hairy black toungue
Inhibition of Nucleic Acid Sythesis
Nucleotide Analogs are effective against rapidly dividing what cells.
Cancer Cells
Inhibition of Protein Synthesis
blocks the catalytic site
Chloramphenicol
Inhibition of Protein Synthesis
__________attaches to ergosterol in fungal membranes, forming pores
Amphotercin B
Prevention of virus attachement
What blocks viral attachment or receptor proteins and is a new are of antimicrobial drug developments?
Attachment antagonists (sugar analogues)
Drugs that treat infections
Antimicrobial agents
Inhibition of Cell Wall Synthesis
Drugs that Interfere with bridges that link NAM subunits in many gram-positives
Vancomycin and Cycloserine
Calvulanic acid is an inhibitor to what enzyme that bacteria make now?
Beta-lactamase
Clavulanic acid is a Beta-Lactamase inhibitor, actin cooperactively with beta-lactas.
Inhibition of Cell Wall Synthesis
blocks secretion of NAG and NAM from cytoplasm
Bacitracin
Narrow-spectrum is effective against how many organisms?
Few organisms
discovered “magic bullet” arsenic compounds that killed microbes
Paul Ehrlich
What test is this and what number is the inhibition?
Minimum inhibitory concentration (MIC) test
1.6 mic inhibitory
What test is this, what number is the zone end on?
.75
E test
aspects of Kirby-bauer and MIC test
Disruptioin to Cytoplasmic Membrane
what inhibits ergosterol synthesis in fungi?
Azoles (fluconazole) and Allylamines (terinafine)
Inhibition of Cell Wall Synthesis
Bind to enymes that cross-linkage NAM subunits
beta-lactam
Inhibition of Nucleic Acid Sythesis
inhibitors of RNA polymerase during transcription affect fungal RNApoly, what drug?
5-fluorocytosine
Inhibition of Cell Wall Synthesis
Creates alanine-alanine etrapeptide crosslinking
Vancomycin
Inhibition of Metabolic Pathways
What interfere with an enzyme HIV needs in its replication cycle
Protease inhibitors
Inhibition of Protein Synthesis
blocks A-to-P site transfer
Erythromycin
Safety and Side Effects
Allergic reactions are rare but may be life threatening leading to what kind of shock?
anaphylactic shock (causing swelling)
discovered Penicillin released from Penicillium
Alexander Fleming
Inhibition of Cell Wall Synthesis
______is part of the core structure of several antibiotic families, the principal ones being the penicillins, cephalosporins, carbapenems, and monobactams, which are, therefore, also called what? Nearly all of these antibiotics work by inhibiting bacterial cell wall biosynthesis.
Beta-lactam
β-lactamantibiotics.
Even fewer drugs of..
antiviral
Inhibition of Nucleic Acid Sythesis
Reverse transcriptase inhibitors act against an enzyme that what virus uses in its replication?
Do not harm poeple because humans lack what?
Acts agaisnt enzyme in HIV
humans lack reverse transcriptase
Inhibition of Cell Wall Synthesis
Disrupts mycolic acid formation in mycobacterial species
Isoniazid and Ethambutol
Inhibition of Cell Wall Synthesis
most common agent prevent..(hint Beta Lactam)
cross-linkage of NAM subunits
