Chapter 20: Antimicrobial Medications Flashcards
Resistantance that develops due to genetic changes, including mutations and horizontal transfers.
Acquired resistance
A compound naturally produced by molds and bacteria that inhibits growth or kills other organisms
Antibiotic
An antibiotic or other chemical that is used to treat an infectious disease and acts by inhibiting or killing microbes; aka antimicrobial drug
Antimicrobial medication
A chemical that is used to treat a viral infection and acts by interfering with the infection cycle of the virus; also called an antiviral drug
Antiviral medication
Describes a chemical that kills a bacteria
Bactericidal
Describes a chemical that inhibits grow of bacteria
Bacteriostatic
An antibiotic that is effective against a wide range of bacteria, generally including both gram-negative and gram-positive
Broad-spectrum antibiotic
A chemical used to treat disease
Chemotherapeutic agent
Resistantance due to inherent characteristics of the organism
Intrinsic (innate) resistance
An antibiotic that is effective against a limited range of bacteria
Narrow-spectrum antibiotic
A plasmid that encodes resistance to one or more antimicrobial medications
R plasmid
Medication used to treat syphilis a long time ago
Salvarsan (arsenic)
Salvarsan and Prontosil are examples of these kinds of drugs
Chemotherapeutic agents
Chemicals that treat disease
Who discovered that Penicillium contained substances that killed bacteria
Alexander Fleming
Most antibiotics come from microorganisms that live where?
In soil
Penicillin G is mainly active against
Gram-positive
Ampicillin kills
Gram-positive & Gram-negative
Causing greater harm to a pathogen than to its host
Selective toxicity
The measure of the relative toxicity of a medication, defined as a ratio of minimum toxic dose to minimum effective dose
Therapeutic index
Antimicrobial that have a (high or low) therapeutic index are safer for humans.
High
The range between the dose used therapeutically and the dose that is toxic
Therapeutic window
A medication that has a high therapeutic index has a (narrow or wide) therapeutic window
Wide
Medications with a low therapeutic index are most used how in humans
Topically
Sulfa drugs prescribed for urinary tract infections don’t kill bacteria but stop them from multiplying, hence they have this kind of antimicrobial action
Bacteriostatic
A disadvantage of broad spectrum antibiotics
They disrupt the natural biome of microflora leaving the paitent at risk for new infections
Combinations of antimicrobials that are neither synergistic nor antagonistic are called
Additive
The rate of elimation of a drug is called
Half life
The time it takes serum concentration of a chemical to reach 50% is called
Half life
___ species lack a cell wall and cannot be treated with penicillin
Mycoplasma
Therapeutic index
Antimicrobial action
Spectrum of activities
Combination effects
Tissue distribution
Half life
Adverse effects
Are all what factors
What one must consider when prescribing an antimicrobial
Cell wall peptidoglycan synthesis
Nucleic acid synthesis
Cell membrane integrity
Metabolic pathways
Protein synthesis
Are all what
Targets of antibacterial medications
B-lactam, glycopeptide, and bacitracin all attack bacteria how
The peptidoglycan during reproduction
A group of antimicrobial medications that inhibit peptidoglycan synthesis have a shared structure called a ______ ring
They group shares the name with this ring also
B-lactam
Penicillin, cephalosporins, carbapenems, and monobactams are this group that interfer with the peptidoglycan synthesis
High therapeutic index
B-lactam
This type of narrow spectrum penicillins are affective against ____ and Penicillin V is more stable in Acid than Penicillin G thus is better taken orally
Natural penicillin
Gram-positive and a few gram-negative
The chemical structure of these antimicrobial drugs protects them from destruction by certain B-lactamases.
Generally more effective against gram-negative
Examples include: CEPHALEXIN & CEFAZOLIN(first generation)
Cephalosporins
Effective against a wide variety of gram bacteria.
Not inactivated by Extended Spectrum B-lactamases
Last resort due to toxicity
B-lactam
Includes: IMIPENEM, ERTAPENEM, MEROPENEM, DORIPENEM
Carbapenems
Vancomycin is this type of antibiotic?
Meaning it affects what
B lactam
Peptidoglycan synthesis
Also, it is a glycopeptide
____ inhibits cell wall synthesis with transport of peptidoglycan precursors across the cytoplasm membrane.
Class of B lactam
Bacitracin
Bactin, glycopeptide antibiotics, monobactam, carbapenems, cephalosporins.
All disrubt bacteria how
The peptidoglycan cell wall
Bacterial ribosome is made of subunits 30S and 50S and is called
70S
Macrolides, Chloramphenicol,
All interfer with bacteria how
Tetracycline , Aminoglycosides
Interfer how
Top: Disruption of 50S of Ribosome
Bottle: Disruption of 30S Ribosome
Streptomycin, gentamicin, neomycin all are examples of a microbial drug that interfere with the 30S Ribosome subunit
Name this group
Aminoglycosides
Bacteriostatic against some Gram-positive and Gram-negative bacteria
bind to the 30S Ribosome, blocking attachments of tRNA, prevents translation.
Tetracyclines
These are used against walking pneumonia and bind the to 50S Ribosome
Preventing transition from occurring
ERYTHROMYCIN, AZITHROMYCIN
Macrolides
Paitents with kidney disease must take medications (more or less) frequently
Less
Chloramphenicol may cause _____ loss of ability to produce blood cells
Aplastic anemia
How is horizontal gene transfer made possible, which action
Conjugation
Penicillins and derivatives
Cephalosporins and derivatives
Carbapenems and derivatives
Glycopeptide antibiotics
Bacitracin
$$$$ total list $$$$
Are all this type of antibiotic that interfere with the peptidoglycan layer
B-lactamas
Aminoglycosides (streptomycin and -mycin derivatives
Tetracycline
Macrolides (erythromycin and -mycin derivatives)
Chloramphenicol
Antibiotics with this function
Interfer with protien synthesis
Fluoroquinolones
(Ciprofloxacin and -floxcin drugs)
Rifamycins
(Rifampin)
Fidaxomicin
Metronidazole
All affect bacteria how
Nucleic acid synthesis
Daptomycin
Polymyxins
All affect bacteria how
Cell membrane integrity
Ethambutol
Isoniazid
Pyrazinamide
Affect which type of bacteria
Mycobacterium tuberculosis
Penicillinase- Resistant Penicillins developed in response to penicillinase from _____ strains
S. Aureus
B-lactam antibiotics completely inhibit ________ enzymes needed to form peptide bridge between adjacent glycine strands
Disrupt cell wall synthesis in reproducing cells
Only effective against actively growing cells
Penicillin-binding proteins
Penicillinase (B-lactamase enzyme) inactive members of the Penicillin family.
_______ produced by more resistant bacteria offer wider variety of resistance of B-lactam medications
Extended-spectrum B-lactamases
(ESBLs)
Gram _____ produce more extensive array of B-lactamases
Negative
Natural penicillins are from Penicillium chrysogenum aka Penicillin __
(Narrow or broad) spectrum
Act against gram-positive and few gram-negative
G
Narrow
MRSA comes from this bacteria
S. aureus
Ampicillin & amoxicillin are (broad or narrow) spectrum
That are inactivated by many B-lactamases
Broad
______ Penicillins have greater activity against Enterobacter & Pseudomonas
But reduced activity against Gram-positive
Destroyed by B-lactamases
Extended-spectrum
This B-lactam antibiotic
Structure makes it resistant to some B-lactamases
Some have low affinity for PBPs of gram positive
5th generation is effective against MRSA
Cephalosporins