ch. 9 micro
jiroveci causes a life threatening systemic mycosis in individuals who are immunocompromised.
Pneumocystis
Which of the following causes a life threatening systemic mycosis in immunocompromised patients?
Pneumocystis jiroveci
Which of the following characteristics applies to protease inhibitors?
Prevent processing of HIV polyprotein
Relapse of malaria results from activation of dormant Plasmodium in the liver. Which of the following drugs is effective in preventing relapse?
Primaquine
Which two of the following characteristics apply to nucleoside reverse transcriptase inhibitors?
Produce faulty viral DNA Are nucleoside analogs
inhibitors prevent HIV maturation by blocking the processing of viral polyproteins.
Protease
Which five of the following are classes of drugs used to manage HIV infection?
Protease inhibitors Nonnucleoside reverse transcriptase inhibitors Nucleoside reverse transcriptase inhibitors Fusion inhibitors Integrase inhibitors
Why are there fewer antiprotozoan drugs than antibacterial drugs?
Protozoa are eukaryotes and thus have fewer targets for drug action
The mechanism of action of oxazolidinones is to inhibit protein synthesis by _____.
preventing the assembly of the 70S initiation complex
Relapse of malaria is prevented by the antiprotozoan drug which targets dormant Plasmodium in the liver.
primaquine
Erythromycin and other macrolide antibiotics interfere with bacterial ______ synthesis.
protein
The antibiotic chloramphenicol interferes with ____________ synthesis in bacteria.
protein
The tetracycline family of antibiotics interfere with __________ synthesis in bacteria.
protein
The antibiotic shown here inhibits bacterial growth by disrupting _____.
protein synthesis
A consequence of HIV remaining dormant in memory T cells of the immune system is that HIV-positive individuals _____.
require drug therapy for life
Fluconazole, amphotericin, and 5-flucytosine are commonly used against ________ mycoses.
systemic
The side effects and toxicity of antiprotozoan drugs in humans is primarily due to _____.
the drugs targeting protozoan enzymes and processes also present in human cells
Vancomycin has the same target as β-lactam antibiotics, the transpeptidation reaction in peptidoglycan synthesis, but it differs in that it _____.
binds to the enzyme's substrate
Treatment of HIV infected patients with nonnucleoside inhibitors reverse transcriptase inhibitors (NNRTIs) results in ______.
blockage of HIV DNA synthesis
Penicillin disrupts cell wall formation by _____.
blocking the formation of peptidoglycan cross links
The acronym "VRE" stands for -resistant enterococci.
vancomycin
The drug of last resort for the treatment of antibiotic resistant Staphylococcus aureus is
vancomycin
The artemisinin mechanism of action appears to be that it _____ in Plasmodium-infected red blood cells that lead to altered hemoglobin catabolism and damage to the electron transport chain.
forms reactive oxygen intermediates
The tetracycline antibiotics are characterized by a _____.
four ring structure with various side chains attached
Many new antimicrobial agents have been discovered in which two soil inhabitants?
fungi and bacteria
The oxazolidinones have a chemical structure featuring a _____.
heterocyclic five-membered ring
Which two of the following antibiotics inhibit protein synthesis by binding to the 50S ribosomal subunit?
macrolides chloramphenicol
Many antifungal agents disrupt _____ synthesis.
membrane
What information do you get from the Etest that you do not get from the Kirby-Bauer test?
minimum inhibitory concentration
The first true antibiotic (a natural microbial product) to be used was
penicillin
The structural component of the vancomycin molecule that is critical for antimicrobial activity is the ________.
peptide portion
It is thought that penicillin blocks the bacterial enzymes that create crosslinks between ____________ polymers (strands) in the cell wall.
peptidoglycan
The fluoroquinolone antibiotics are characterized by a fluorinated _______.
4-quinolone ring
Macrolide antibiotics interfere with protein synthesis by binding to _____.
50S ribosomal subunit
The antimalarial drug _____ has its origins in traditional Chinese medicine, and is now an effective and inexpensive treatment.
artemisinin
The antimicrobial activity of chloramphenicol results from its binding to _____.
50S ribosomal subunit
The minimal __________ concentration is the level of an antimicrobial agent required to kill a targeted pathogen.
lethal
Which two of the following are NOT targets of antibacterial drugs that inhibit nucleic acid synthesis?
80S Ribosome Dihydrofolate reductase
A combination of which two drugs are recommended for the treatment of malaria?
Artemisinin derivative Quinine drug
The antimicrobial activity of the tetracycline family of antibiotics results from their binding to _______.
30S ribosomal subunit
Which two of the following statements regarding artemisinin are correct?
A semisynthetic artemisinin is an effective, inexpensive treatment for malaria. Artemisinin originally derived from traditional Chinese medicine.
Which two of the following statements about antimetabolites are true?
Antimetabolites compete with a natural substrate for binding at the active site. Antimetabolites have a similar structure to the substrate of the target enzyme.
The World Health Organization recommends a combination of a quinine drug and a derivative of which of the following compounds in the treatment of malaria?
Artemisinin
Antimetabolites are classified as ________ and ________ drugs.
Bacteriostatic Broad spectrum drugs
Which of the following is the mode of action of trimethoprim?
Blocks folic acid synthesis
Which two of the following characteristics apply to the antiprotozoan drug chloroquine?
Causes build up of toxic heme metabolites DIsrupts plasmodial DNA
Which two of the following statements are true?
Currently there are fewer antifungal agents than antibacterial agents. Fungal cells are more similar to human cells than to bacterial cells.
mycoses are the most difficult to control.
Deep
inhibitors are a category of drugs that block HIV entry into host cells.
Fusion
The side effects and toxicity of antiprotozoan drugs results from the fact that protozoans and humans are both members of Domain and have similar enzymes, processes, and pathways.
Eukaryota
Which three of the following are commonly used to treat systemic mycoses?
Fluconazole Amphotericin B 5-Flucytosine
Why are there fewer antifungal drugs than antibacterial drugs?
Fungal cells are more similar to human cells than bacterial cells.
Which two of the following characteristics do not apply to macrolide antibiotics?
Has a four ring structure Inhibits DNA replication
Which of the following characteristics applies to antifungal drugs?
Have a low therapeutic index
Which statement about the antiprotozoan activity of clindamycin and paromomycin is true?
Interfere with protein synthesis
Which of the following is NOT a mode of action of chloroquine?
Interferes with protein synthesis
Which of the following characteristics does not apply to tetracycline?
Is bactericidal
Which of the following are possible side effects of aminoglycoside antibiotic use?
Loss of balance Allergic reaction
Which two of the following characteristics apply to antifungal agents?
Many are toxic to human cells Most are fungistatic
Which of the following are targets of antifungal agents?
Membrane synthesis
Which two of the following characteristics apply to aminoglycosides?
Synthesis of abnormal proteins Bind to 30S ribosomal subunit
Which of the following statements about carbapenems and monobactams is false?
These drugs are heavily used clinically.
Which two of the following are examples of superficial mycoses?
Toenail fungus Oral candidiasis (thrush)
Which two of the following are targets of antibacterial drugs that inhibit nucleic acid synthesis?
Topoisomerase DNA Polymerase
A zone of inhibition is _____.
a clear ring around an antibiotic disk in the Kirby-Bauer assay
The type of antibiotic resistance that is due to a change in the genome of a bacterium that converts it from a sensitive cell to a resistant cell is called resistance.
acquired
Based on its chemical structure, the antibiotic shown here belongs to the class of drugs termed _____.
aminoglycosides
Lincosamine antibiotics have a broad spectrum of activity against _____.
anaerobes
A substance that blocks the functioning of a specific biochemical pathway is called a(n) _____.
antimetabolite
A(n) ___________ is an antimicrobial substance that antagonizes or blocks the function of a specific biochemical pathway.
antimetabolite
The therapeutic index of a protein synthesis inhibitor is less than the therapeutic index of a cell wall inhibitor because _____.
bacterial cells and host cells both use ribosomes for protein synthesis
Oxazolidinones are _____.
bacteriostatic
Chloramphenicol is a _________ spectrum antibiotic.
broad
Drugs that are effective against a wide variety of pathogens are called _____ drugs.
broad-spectrum
The highest therapeutic index is found with antimicrobial drugs that target ___________ __________ synthesis.
cell wall
All aminoglycoside antibiotics contain a(n) ____________ ring and amino sugars.
cyclohexane
The aminoglycoside antibiotics are characterized by the presence of amino sugars and a _____.
cyclohexane ring
The artemisinin mechanism of action appears to be that it forms reactive oxygen intermediates in Plasmodium-infected red blood cells that lead to _____ [Choose two]
damage to the electron transport chain altered hemoglobin catabolism
Treatment of HIV infected cells with nucleoside reverse transcriptase inhibitors results in the production of faulty viral
dna
The concept of a "magic bullet," a chemical that would selectively destroy pathogens without harming human cells, was put forth by Paul ___________ , whose research sparked the era of modern antimicrobial chemotherapy.
ehrich
Antifungal agents that contain azoles inhibit synthesis and disrupt fungal membrane permeability.
ergosterol
The are a family of synthetic antibacterial drugs that contain a fluorinated 4-quinolone ring.
fluoroquinolones
Sulfonamides disrupt the synthesis of ________ acid, a precursor of purines.
folic
The minimal _______ concentration is the level of an antimicrobial agent required to stop the growth of a targeted pathogen.
inhibitory
The macrolides are a family of antibiotics that are characterized by a(n) ring that is linked to one or more sugars.
lactone
Vancomycin is classified as a ________ spectrum drug because it is only effective against Gram positive bacteria.
narrow
Drugs that are only effective against a limited variety of pathogens are called _____ drugs.
narrow-spectrum
The ultimate result of penicillin treatment of sensitive bacteria is cell-death resulting from ______.
osmotic lysis
A successful antimicrobial agent has __________ ___________ , the ability to kill or inhibit microbial pathogens with little or no damage to the host.
selective toxicity
The structure of sulfa drugs is characterized by a(n) _____.
similarity to p-aminobenzoic acid
Azoles are antifungal drugs that block _____ synthesis.
sterol
Antimetabolites are similar in structure to the _________ of key enzymes and compete with them for binding at the enzyme active site.
substrate
Antimetabolites are similar in structure to the ____________ of key enzymes and compete with them for binding at the enzyme active site.
substrates
The class of antibiotics that are structural analogues of p-aminobenzoic acid is the _____.
sulfonamides
Toenail fungus and thrush are classified as mycoses.
superficial
On this Petri dish showing the interaction of two microorganisms, the organism indicated by the letter A is _____.
susceptible to compounds produced by organism B
Sulfa drugs and trimethoprim are often used together because lower dosages of each drug can be used. This type of interaction between drugs is called a(n) _________ drug effect.
synergistic
HIV-infected individuals require drug therapy for life because _____.
the virus remains dormant in immune cells
Due to the similarities of human and fungal cells, most antifungal drugs have a low index.
therapeutic
The degree of selective toxicity can be expressed in terms of
therapeutic and toxic dose
The semisynthetic penicillins nafcillin, oxacillin, and methicillin are more difficult for β-lactamase enzymes to degrade because _____.
they have bulkier side chains than natural penicillin