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109 Cards in this Set
- Front
- Back
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what is the goal of antimicrobial chemotherapy? |
Administera drug to an infected person that destroys the infective agent without harmingthe host’s cells
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does the perfect drug exist |
no |
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•New drugs are created by chemically altering the structure of naturally occurring antibiotics to create drugs are called (blank)
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semisynthetic |
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Some natural compounds cannot be obtained without the destruction of a habitat or organismal population are called (blank)
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synthetic drugs |
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what three factors must be known before starting antimicrobial therapy |
-Theidentity of the microorganism causing the infection
–Thedegree of the microorganism’s susceptibility (sensitivity) to various drugs –Theoverall medical condition of the patient |
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•The______ ______ test shows antimicrobial susceptibility using large agar plates,a bacterial lawn, and antibiotic-infused discs.
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Kirby-Bauertechnique |
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state the main goal of antimicrobial treatment |
to administer a drug to an infected person, which destroys the infective agent without harming the host's cells |
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identify sources of the most commonly used antimicrobial drugs |
-Streptomyces and Bacillus is bacteria. -From molds, Penicillum and cephalosporium |
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list two methods for testing antimicrobial susceptibility |
-Kirby-Bauer technique -tube dilution tests |
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what is therapeutic index |
the ratio of the dose of the drug that is toxic to humans to its minimum effective (therapeutic) dose. The closer these two figures are to each other (the smaller the ratio), the greater potential for toxic drug reactions |
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identify whether a high or low index is preferable in a drug |
TI of 1.1 is a riskier choice than a TI of 10 -when drugs have similar MICs, the drug with the highest TI has the widest margin of safety |
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(blank) should kill or inhibit microbial cells without simultaneously damaging host tissues |
selectively toxic |
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list a drug with excellent selective toxicity |
penicillin |
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(blank) block the synthesis of the cell wall found only in bacteria |
penicillin |
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list the metabolic targets of chemotherapeutic agents |
-Inhibitionof cell wall synthesis
–Inhibitionof nucleic acid (DNA and RNA) structure and function –Inhibitionof protein synthesis –Interferencewith cell membrane structure or functionInhibition of folicacid synthesis |
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True/False: An antibiotic that acts on the bacterial cell wall will have no effect on a human cell
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True |
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True/False: An antibiotic that acts on the bacterial ribosome will have no effect on a human cell.
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false |
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List and describe one antibiotic from each of the following categories:
–Drugs that target cell wall synthesis –Drugs that target protein synthesis –Drugs that target DNA or RNA -Drugs that target folic acid synthesis |
-Drugs that target cell wall synthesis - Penicillin -Cephalosporin Drugs that target protein synthesis - tetracyclin, glycycline –Drugs that target DNA or RNA - Fluoroquinine -Drugs that target folic acid synthesis - sulfonamides |
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explain the concept of selective toxicity |
-antimicrobial drugs should kill or inhibit microbial cells without simultaneously damaging host tissues -central concept in antibiotic treatment -the best drugs in current use block the actions or synthesis of molecules in microorganisms but not vertebrate cells |
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describe the 5 major targets of antimicrobial agents and list major drugs associated with each |
1. inhibition of cell wall synthesis; penicillin, cephalosporins, carbapenems 2. inhibition of nucleic acid (RNA and DNA) structure and function; Fluoroquinolones 3. inhibition of protein synthesis; aminoglycosides, tetracyclines, glycylcyclines, macrolides 4. interference with cell membrane structure or function; polymyxins 5. inhibition of folic acid synthesis; sulfonamides |
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identify which categories of drugs are most selectively toxic, and explain why they exhibit this effect |
... |
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(blank) are effective against more than one group of bacteria |
broad spectrum drugs |
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list an example of a broad spectrum drug |
tetracyclines
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(Blank) drugs onlytarget a specific group |
Narrow spectrum drugs
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list an example of narrow spectrum drugs |
polymyxinand penicillins
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Penicillins consist of what 3 things? |
-Thiazolidine ring
-Betalactam ring -Variable side chain |
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(blank) havea beta-lactam ring that can bechemically altered |
Cephalosporins |
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(Blank) are composed of one or more amino sugars and an aminocyclitol ring |
The aminoglycoside drugs
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(Blank) are natural parent compound and synthetic derivatives |
Tetracyclines |
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List the side effects of Tetracyclines |
-Side effects:
-Gastrointestinal disruption -Deposition in hard tissues |
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(Blank) are newer derivatives of tetracyclines |
Glycylcyclines
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Glycylcyclines are effective against bacteria that have become resistant to (blank)
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tetracyclines
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(blank) are the first modern antimicrobial drugs |
Sulfonamides or sulfadrugs
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(blank) are high potency and are readily absorbed from the intestine |
Fluoroquinolones
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List some side effects of Fluoroquinolones |
•Seizures and other brain disturbances
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(blank) are derived from Bacillus polymyxa and Toxic to the kidney |
Polymyxins
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list an antimalarial drugs |
Quinine |
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list a chemotherapyfor other protozoan infections |
–Metronidazole: amoebicide
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list different antihelminthic drug therapy |
–Mebendazole and albendazole
–Pyrantel Praziquantel |
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Three major modes of action of antiviral Chemotherapeutic Agents
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-Barring penetration of the virus into the host cell
–Blocking the transcription and translation of viral molecules –Preventing maturation of viral particles |
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Name one antibiotic drugs that target the cell wall
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Penicillin |
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Name one antibiotic drugs that target protein synthesis
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the aminoglyclycoside drugs: tetracyclines, glycylcyclines |
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Name one antibiotic drugsthat target folic acid synthesis
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sulfonamides or sulfa drugs |
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Name one antibiotic drugs that target DNA or RNA
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Fluoroquinolones |
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Name one antibiotic drugs that target cell membranes
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Polymyxins |
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True/False: Antifungal and antihelminthic drugs can be toxic to human cells.
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True - **they are eukaryotic** |
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True/False: There are as many antiviral drugs as there are antibiotics
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... |
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distinguish between broad spectrum and narrow spectrum antimicrobials and explain the significance of the distinction |
broad spectrum - effective against more than one group of bacteria example - tetracyclines narrow spectrum - only target a specific group examples: polymyxin and penicillins |
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trace the development of penicillin antimicrobials and identify which microbes they are effective against |
... |
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describe the action of beta-lactamases, and explain their importance in drug resistance |
... |
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list examples of other beta-lactam antibiotics |
... |
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describe common cell wall antibiotics that are not in the beta-lactam class of drugs |
... |
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identify the ribosomal targets of several antibiotics that inhibit protein synthesis |
... |
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identify the cellular target of quinolones and provide two examples of these drugs |
... |
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name two drugs that target the cellular membrane |
... |
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describe the unique methods used to treat biofilm infections |
... |
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name the 4 main categories of antifungal agents and provide one example of each |
... |
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describe 2 major modes of action of antiviral drugs |
... |
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(blank) are Plasmids that are transferred through conjugation, transformation, or transduction |
Resistance (R) factors
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(Blank) are duplicated and inserted from one plasmid to another or from the plasmid to the chromosome |
–Transposable drug resistance sequences (transposons)
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How Does Drug Resistance Develop?
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•Sharing of resistance genes accounts for the rapid proliferation of drug-resistant species.
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(blank) is when thehospital environment continually exposes pathogens to a variety of drugs |
The hospital factor |
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True/False: Nearly 80% of all antibiotics in the US are given to livestock |
True |
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List 2 long-term strategies to control drug resistance |
- Restrictionof the use of first-line antibiotics
–Enhancedsurveillance mechanisms: |
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List 2 New Approaches to Antimicrobial Therapy |
-Past approach -Novel approach -Low Tech solutions |
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(blank) approach is disabling host molecules that the invaders use to enhance their position |
novel approach |
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(blank) approach finds new targets in the bacterial cell and customizes drugs that aim for these new targets |
past approach |
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(blank) are preparations of live microorganisms fed to animals and humans to improve intestinal biota |
probiotics |
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list an example of a probiotic |
probiotic yogurt |
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(blank) are nutrients that encourage the growth of beneficial microbes in the intestine |
Prebiotics
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list an example of prebiotics |
–fructans encourage the growth of Bifidobacterium in the large intestine and discourage the growth of pathogens
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•True/False: Bacteria can be resistant to antibiotics without ever encountering the drug.
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... |
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Listand describe the five mechanisms of antibiotic resistance
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1. New enzymes are synthesized inactivate the drug, only occurs when new genes are acquired 2. permeability or uptake of the drug into a bacterium is decreased, usually occurs via mutation 3. drug is immediately eliminated, usually occurs via acquisition of new genes 4. binding sites for drug are decreased in number or affinity, can occur via mutation or acquisition of new genes 5. an affected metabolic pathway is shut down or alternative pathway is used, occurs due to mutation of original enzyme or enzymes |
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•True/False: The majority of antibiotics prescribed to human are for viral infections.
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... |
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•Nearly80% of all antibiotics in the US are given to ________.
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livestock |
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discuss two possible ways that microbes acquire antimicrobial resistance |
-Resistance through spontaneous mutation -resistance through horizontal transfer -Sharing of resistance genes accounts for the rapid proliferation of drug-resistant species |
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list 5 cellular or structural mechanisms that microbes use to resist antimicrobials |
... |
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discuss at least three novel microbial strategies that are under investigation |
... |
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________ discovered penicillin when he observed clearing around Penicillium notatum on bacterial plates.
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Alexander Fleming
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Salvarsan, the first synthetic chemotherapeutic agent, was discovered by
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Paul Ehrlich
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________ are the primary sources of most antibiotics
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Fungi and bacteria
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(blank) should be considered before antimicrobial therapy can begin |
the cost of the antimicrobial therapy
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Antimicrobials are classified by what?
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-chemical composition
-source or origin -site of action. |
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Characteristics of an ideal antimicrobial include that it
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is microbicidal
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A drug with a _________ therapeutic index (TI) is safer for use in a patient
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higher
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what should be taken into consideration before a physician administers an antibiotic to a patient? |
-patient age
-history of allergies to antibiotics -whether the patient is pregnant |
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True/false: Cephalosporins do not target the bacterial ribosome |
true |
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Cephalosporins and penicillins act on the cross-linkages in peptidoglycan. This usually results in what?
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cell lysis
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The majority of antimicrobials are effective against what?
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bacteria
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Microbes can become drug resistant and lose their sensitivity to a drug through the acquisition of resistance factors. Drug resistance can take the form of
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change in drug binding sites
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Bacterial drug resistance emerges in populations due to
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gene transfer
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Bacterial drug resistance could be reduced by
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washing hands more often with antibacterial soaps
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________ chemotherapy targets helminthes and protozoans
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Antiparasitic
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Antiviral chemotherapeutic agents have a mode of action which
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-prevents viral maturation
-transcription and translation of viral molecules -disallows entry of virus into the cell. |
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(blank) is used most often in cases of allergy to penicillins or antibiotic resistance? |
Vancomycin
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________ is an anti-HIV medication that blocks DNA synthesis
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Acyclovir
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A new antiviral drug called DRACO created at MIT detects _______ in cells, indicating viral replication, and causes the cell to self destruct.
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long strands of dsDNA
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________ are preparations of live microorganisms fed to animals to improve intestinal biota
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Probiotics
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Prophylaxis is the use of antimicrobial drugs to
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prevent infection
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true/false: Fungal infections are more difficult to treat because fungal cells are so similar to animal cells |
true |
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true/false: The three major side effects of antimicrobials are toxicity to organs, allergic reactions, and suppression or alteration of blood cells |
false |
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true/false: The Kirby-Bauer test identifies agents that can be used to fight specific bacteria |
true |
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true/false: Azoles are used to fight malarial parasites |
false |
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true/false: Some antiviral agents are activated by viral enzymes |
true |
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true/false: MIC determines how much antimicrobial agent to use in vivo |
false |
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true/false: Bacteria in biofilms can be treated with the same antibiotics as bacteria causing localized or systemic infections |
false |
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true/false: In vitro testing of an antibiotic to determine its antimicrobial activity is sufficient before using the drug in vivo |
false |
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true/false: Broad-spectrum antibiotics are always the most effective choice for treating a bacterial infection |
false |
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true/false: Tamiflu and Relenza must be taken early in an influenza infection in order to be effective |
true |
