Term
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Definition
| chemically altered antibiotics- that are more effective, longer lasting, or easier to administer than naturally occurring antibiotics |
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Term
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Definition
| antimicrobials that are compeletely synthesized in a laboratory |
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Term
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Definition
| antimicrobial agents that are produced naturally by an organism |
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Term
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Definition
| an effective antimicrobial agent must be more toxic to a pathogen than to the pathogen's host. It is possible b/c of differences in structure or metabolism between the pathogen and its host. |
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Term
| The 5 mechanisms by which antimicrobial drugs affect the growth of pathogens |
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Definition
- Inhibition of Cell Wall synthesis
- Inhibition of protein synthesis
- Disruption of cytoplasmic membranes
- Inhibition of Metablic pathways
- Inhibition of Nucleic Acid Synthesis
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Term
Inhibition of Cell Wall synthesis
Purpose |
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Definition
the most common antibacterial agents act by preventing the cross-linkage of NAM subunits. Most prominent of these drugs is BETA-LACTAMS, Vancomycin, Cycloserine and Bacitracin
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Term
Beta-Lactams
a.k.a
Penicilins & cephalosporins |
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Definition
Beta-Lactams inhibit peptidoglycan formation by irreversibly binding to the enzymes that cross-link NAM subunits
Dorment cells are not effected. Bacterial cells have to be growing or reproducing to have effect |
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Term
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Definition
| molecules that are cross linked by short eptide chains extending between NAM subunits, which in turn make up the cell wall of a cell |
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Term
| Vancomyosin & Cycloserine |
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Definition
They directly interfere with particular alanine-alanine bridges that link the NAM subunits in many Gram-positive bacteria. In turn causing cell lysis.
Dorment cells are not effected. Bacterial cells have to be growing or reproducing to have effect |
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Term
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Definition
Blocks the transport of NAG and NAM from the cytoplasm out to the wall. End result is cell lysis.
Dorment cells are not effected. Bacterial cells have to be growing or reproducing to have effect |
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Term
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Definition
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Term
Aminoglycosides
a.k.a
streptomycin and gentamicin |
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Definition
| They change the shae of the 30S subunit, making it impossible for the ribosome to read the codons of mRNA correctly. |
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Term
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Definition
| block the tRNA docking site (A site), which then prevents the incorporation of additional amino acids into a growing polypeptide |
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Term
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Definition
| block the enzymatic site of the 50S subunit, which prevents translation |
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Term
Lincosamids
Streptogramins
Macrolides |
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Definition
| bind to a different portion of the 50S subunit, preventing movement of the ribosome from one codon to the next. End result is frozen translation and protein synthesis is halted. |
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Term
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Definition
| drugs that block protein synthesis |
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Term
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Definition
| antimicrobial drug that works to stop proteins synthesis by blocking initiation of translation |
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Term
| Disruption of Cytoplasmic Membranes |
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Definition
| some antibacterial drugs, such as the short ploypeptide gramicidin, disrupts the cytoplasmic membranes of a targeted cell. Often this is achieved by forming a channel through the membrane, damaging its integrity |
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Term
| Inhibition of Metabolic Pathways |
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Definition
| stopping or interfering the the metabolic break down in the bacteria |
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Term
| Inhibition of Nucleic Acid Synthesis |
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Definition
Drugs that function to block either the replication of DNA or its transcription into RNA.
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Term
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Definition
| other compounds that can act as antimicrobials by interfering with the function of nucleic acids |
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Term
| Prevention of Virsus Attachement |
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Definition
| Viruses must attach to their host's cells via the chemical interation between attachment proteins on the pathogen and complementary receptor proteins. when sites are blocked by analogs, viruses can neither attach to nor enter their hosts's cells. |
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Term
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Definition
| the number of different kinds of pathogens a drug acts against |
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Term
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Definition
| those drugs that are effective agains many different kinds of pathogens |
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Term
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Definition
| Drugs that work against only a few kinds of pathogens |
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Term
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Definition
| the use of broad-spectrum antmicrobials is not always as desirable as it might seem. they also open the door to serious secondary infections by transient pathogens or superinfections by members of the normal microbiota unaffected by the antimicrobial |
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Term
Diffusion Susceptibility Test
a.k.a
Kirby-Bauer test |
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Definition
| involves uniformly inoculating Petri plate with a standardized amount of the pathogen in question. then small disks of paper containing standard concentratiosn of the drugs to be tested are firmly arranged on the surface of the plate. the plate is incubated, and the bacteria gorw and reproduce to form "lawn" everywhere but the areas where effective antimicrobial drugs diffuse through the agar. |
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Term
Minimum Inhibitory Concentration Test
a.k.a
MIC
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Definition
| the smallest amount of the drug that will inhibit growth and reproduction of the pathogen |
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Term
Minimum Bactericidal Concentration Test
a.k.a
MBC |
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Definition
| determines the amount of drug required to kill the microbes rather than just the amount to inhibit it |
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Term
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Definition
a plastic strip contains a gradient of the antimicrobial agent of interest. the MIC is estimated to be the concentration printed on the strip where the zone of inhibition intersects the strip.
This test combines the Kirby-Bauer and MIC test. |
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Term
| The 3 main types of side effects of antimicrobial therapy |
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Definition
- Toxicity
- Allergies
- Disruption of normal microbiota
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Term
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Definition
| antimicrobials can not only harm the microbes but us humans as well. And many have toxic side effects. |
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Term
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Definition
| some drugs can trigger allergic reactions in the pateints immune system. Very rarely do these allergic reaction cause death. |
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Term
| Disruption of Normal Microbiota |
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Definition
| drugs that disrupt normal microbiota and their microbial antagonism of oppertunistic pathogens may result in secondary infections. |
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