Chapter 9 BIOL 3702

The antimicrobial activity of chloramphenicol results from its binding to _____. Multiple choice question. 30S ribosomal subunit 50S ribosomal subunit messenger RNA RNA polymerase topoisomerase

50S ribosomal subunit

Which two of the following are NOT targets of antibacterial drugs that inhibit nucleic acid synthesis? Multiple select question. DNA Polymerase 80S Ribosome Dihydrofolate reductase Topoisomerase

80S Ribosome Dihydrofolate reductase

Which of the following statements concerning antivirals is false? Multiple choice question. Antivirals rarely cure a disease. Antivirals are often referred to as antibiotics. Many antivirals only limit the duration of the illness. Antivirals usually disrupt the viral replication cycle.

Antivirals are often referred to as antibiotics.

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? Multiple choice question. Metronidazole Artemisinin Griseofulvin Atovaquone

Artemisinin

A combination of which two drugs are recommended for the treatment of malaria? Multiple select question. Griseofulvin Artemisinin derivative Metronidazole derivative Quinine drug

Artemisinin derivative Quinine drug

Adenine arabinoside, found in the vidarabine ointment that is used to treat herpes infections and shingles, interferes with the synthesis of viral _____.

DNA

Which two of the following are targets of antibacterial drugs that inhibit nucleic acid synthesis? Multiple select question. DNA Polymerase 80S Ribosome Dihydrofolate reductase Topoisomerase

DNA Polymerase Topoisomerase

Acyclovir blocks the activity of viral _____ _____ enzyme.

DNA or herpes/polymerase or simplex

Upon phosphorylation, the antiviral drug acyclovir inhibits viral _____. Multiple choice question. release RNA polymerase DNA polymerase penetration

DNA polymerase

Which two of the following characteristics apply to nonnucleoside reverse transcriptase inhibitors (NNRTIs)? Multiple select question. Produce faulty viral DNA Are nucleoside analogs Inhibit reverse transcriptase Selectively bind to reverse transcriptase

Inhibit reverse transcriptase Selectively bind to reverse transcriptase

Which two of the following statements are true? Multiple select question. a. Fungal cells are more similar to human cells than to bacterial cells. b. Bacterial cells are more similar to human cells than to fungal cells. c. Currently there are fewer antibacterial agents than antifungal agents. d. Currently there are fewer antifungal agents than antibacterial agents.

a. Fungal cells are more similar to human cells than to bacterial cells. d. Currently there are fewer antifungal agents than antibacterial agents.

Penicillin disrupts cell wall formation by _____. Multiple choice question. a. blocking the formation of peptidoglycan cross links b. binding to the 30S ribosomal subunit c. hydrolyzing the peptidoglycan chains d. repressing bacterial genes for cell wall synthesis

a. blocking the formation of peptidoglycan cross links

The drugs that target the cell wall have a high therapeutic index because human cells _____. Multiple choice question. a. do not have cell walls b. have different sized ribosomes compared to microbes c. have different enzymes for cell wall synthesis d. are aerobic

a. do not have cell walls

Which two of the following statements about antimetabolites are true? Multiple select question. a. Antimetabolites form a precipitation complex with a natural substrate of enzyme. b. Antimetabolites have a similar structure to the substrate of the target enzyme. c. Antimetabolites compete with a natural substrate for binding at the active site. d. Antimetabolites bind to 30S ribosomal subunit and block formation of the initiation complex.

b. Antimetabolites have a similar structure to the substrate of the target enzyme. c. Antimetabolites compete with a natural substrate for binding at the active site.

Methods to detect antimicrobial drug resistance include the use of the polymerase chain reaction (PCR). This method is appropriate because _____. Multiple choice question. a. PCR can quantitate the appropriate level of drug to use b. PCR is often correlated with antibiotic resistance c. drug resistance determinants are genetically encoded d. antibiotic-modifying enzymes interfere with PCR

c. drug resistance determinants are genetically encoded

The most selective antibiotics in use target the bacterial _____ _____.

cell wall

The drugs that target the cell wall have a high therapeutic index because human cells _____. Multiple choice question. do not have cell walls have different enzymes for cell wall synthesis have different sized ribosomes compared to microbes are aerobic

do not have cell walls

Antimetabolites are similar in structure to the _____ of key enzymes and compete with them for binding at the enzyme active site.

substrate or substrates

A zone of inhibition is _____. Multiple choice question. a. the laboratory space around the flame where contamination is unlikely to occur b. a clear ring around an antibiotic disk in the Kirby-Bauer assay c. a zone around a bacterial colony that is resistant to antibiotic d. the space between a bacterial inner and outer membrane

b. a clear ring around an antibiotic disk in the Kirby-Bauer assay

Treatment of HIV infected patients with nonnucleoside inhibitors reverse transcriptase inhibitors (NNRTIs) results in ______. Multiple choice question. blockage of HIV DNA synthesis inhibition of HIV release production of faulty HIV DNA blockage of HIV polyprotein processing

blockage of HIV DNA synthesis

he sulfonamides inhibit the growth of a wide variety of bacteria and are classified as _____-spectrum drugs.

broad

Drugs that are effective against a wide variety of pathogens are called _____ drugs. Multiple choice question. broad-spectrum bactericidal narrow-spectrum bacteriostatic

broad-spectrum

True or false: The lower the therapeutic index, the better the chemotherapeutic agent is.

false

True or false: The macrolide antibiotics are bactericidal.

false

True or false: There are more antiprotozoan agents than antibacterial agents.

false

As a general rule, the _____ (greater/smaller) therapeutic index, then the better the antimicrobial agent.

greater or larger

In the dilution susceptibility test, the minimum _____ concentration is the lowest concentration of antibiotic that results in no growth after incubation.

inhibitory

The minimal _____ concentration is the level of an antimicrobial agent required to stop the growth of a targeted pathogen.

inhibitory

The term bactericidal means that the antimicrobial agent _____ bacteria, and bacteriostatic means that it reversibly _____ the growth of the bacteria.

kills inhibits

Most penicillin resistant bacteria produce enzymes called penicillinases that hydrolyze the β-_____ ring of penicillin and render the molecule ineffective.

lactam

The most critical portion of the penicillin molecule is the β-_____ _____ , which is essential for the antimicrobial activity of the drug.

lactam ring

The macrolides are a family of antibiotics that are characterized by a(n) _____ ring that is linked to one or more sugars.

lactone

The macrolide antibiotics are characterized by a _____. Multiple choice question. β-lactam ring with various side chains attached two ring structure with amino sugars attached cyclohexane ring with various side chains attached lactone ring with one or more sugars attached

lactone ring with one or more sugars attached

In the absence of a drug, a population of drug-resistant bacteria should become _________ resistant to the drug. Multiple choice question. more less

less

The minimal _____ concentration is the level of an antimicrobial agent required to kill a targeted pathogen.

lethal

Bacteria sensitive to penicillin are killed as a result of osmotic _____.

lysis

The acronym "MRSA" stands for _____-resistant Staphylococcus aureus.

methicillin

The concentration of drug necessary to prevent the growth of a pathogen is called the _____. Multiple choice question. toxic dose minimal inhibitory concentration therapeutic index minimal lethal concentration

minimal inhibitory concentration

The concentration of drug necessary to kill a pathogen is called the _____. Multiple choice question. minimal lethal concentration LD50 therapeutic index minimal inhibitory concentration

minimal lethal concentration

What information do you get from the Etest that you do not get from the Kirby-Bauer test? Multiple choice question. which antibiotic the organism is resistant to minimum lethal concentration whether the effect is static or cidal minimum inhibitory concentration

minimum inhibitory concentration

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. Multiple choice question. narrow-spectrum bacteriostatic bactericidal broad-spectrum

narrow-spectrum

Antiviral agents are _____ referred to as "antibiotics." Multiple choice question. often never sometimes always

never

The ultimate result of penicillin treatment of sensitive bacteria is cell-death resulting from ______. Multiple choice question. osmotic lysis metabolic starvation inhibition of DNA replication lack of protein synthesis

osmotic lysis

Select all that apply Which of the following antibiotics inhibit protein synthesis by binding to the 50S ribosomal subunit? Multiple select question. oxazolidinones macrolides tetracyclines chloramphenicol aminoglycosides

oxazolidinones macrolides chloramphenicol

The mechanism of action of _____ is three-fold: It inhibits the transpeptidase reaction in peptidoglycan biosynthesis, activates bacterial autolytic enzymes, and stimulates holins to form holes in the plasma membrane.

penicillin

It is thought that penicillin blocks the bacterial enzymes that create crosslinks between _____ polymers (strands) in the cell wall.

peptidoglycan or nam-nag or nag-nam

Select all that apply Methods to test bacterial isolates for drug resistance include _____. Multiple select question. whole genome sequencing polymerase chain reaction Western blot using antibiotic probes enzyme detection kits with a chromophore

polymerase chain reaction enzyme detection kits with a chromophore

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

Aminoglycosides interfere with _____. Multiple choice question. nucleic acid synthesis carbon metabolism protein synthesis cell wall synthesis

protein synthesis

The antiviral agent tamiflu blocks _____. Multiple choice question. release of new virus particles from host adsorption of virus onto the host cell surface replication of the viral genome uncoating of the viral capsid

release of new virus particles from host

A consequence of HIV remaining dormant in memory T cells of the immune system is that HIV-positive individuals _____. Multiple choice question. require changing antivirals monthly require drug therapy for life take years to eventually be cured must be continually monitored for antiviral effectiveness

require drug therapy for life

A successful antimicrobial agent has_____ _____ , the ability to kill or inhibit microbial pathogens with little or no damage to the host.

selective toxicity

The ability to kill or inhibit microbial pathogens while causing minimal damage to the host is called _____. Multiple choice question. broad spectrum metabolic antagonism selective toxicity narrow spectrum

selective toxicity

Naturally occurring antibiotics that have been chemically modified are called ______. Multiple choice question. semi-synthetic therapeutic synthetic organic

semi-synthetic

Naturally occurring antibiotics that have been chemically modified by the addition of chemical groups are called _____ antibiotics.

semisynthetic

Toenail fungus and thrush are classified as _____ mycoses.

superficial

Vidarabine ointment contains adenine arabinoside, an antiviral agent that disrupts ______. Multiple choice question. processing of viral proteins synthesis of viral DNA synthesis of viral proteins viral integration into host chromosome

synthesis of viral DNA

_____ mycoses are the most difficult to control.

systemic

An important limitation to the use of lincosamine antibiotics is that they can support the overgrowth of _____. Multiple choice question. E. coli C. difficile Pseudomonas species Mycoplasma species

C. difficile

Which two of the following characteristics apply to the antiprotozoan drug chloroquine? Multiple select question. Causes build up of toxic heme metabolites Used to treat amoebic encephalitis DIsrupts plasmodial DNA Binds to and disrupts RNA expression and function

Causes build up of toxic heme metabolites DIsrupts plasmodial DNA

Which of the following characteristics applies to antifungal drugs? Multiple choice question. Have a medium range therapeutic index Have a low therapeutic index Have a high therapeutic index

Have a low therapeutic index

Which two of the following characteristics apply to tamiflu? Multiple select question. Inhibits hemagglutinin Inhibits reverse transcriptase Inhibits neuraminidase Blocks release of new viruses from host

Inhibits neuraminidase Blocks release of new viruses from host

Which of the following is NOT a mode of action of chloroquine? Multiple choice question. Eradicates protozoan asexual stages Interferes with protein synthesis Interferes with cell membrane production Inhibits malarial heme polymerase

Interferes with protein synthesis

In the dilution susceptibility test, the lowest concentration of antibiotic that results in no growth of the test bacterium is the _____. Multiple choice question. MLC TLC TIC MIC

MIC

Antiprotozoan drugs are NOT known to target which of the following? Multiple choice question. Metabolic processes Nucleic acid synthesis Membrane synthesis

Membrane synthesis

Which two of the following are targets of antiprotozoan agents? Multiple select question. Nucleic acids Metabolic processes Cell wall structure Membrane sterol synthesis

Nucleic acids Metabolic processes

Why are there fewer antiprotozoan drugs than antibacterial drugs? Multiple choice question. Protozoan infections are rare and non-life threatening Protozoa are protected from drugs by a thick cell wall Protozoa are eukaryotes and thus have fewer targets for drug action Protozoa have extremely efficient detoxification pathways

Protozoa are eukaryotes and thus have fewer targets for drug action

HIV-infected individuals require drug therapy for life because _____. Multiple choice question. antiviral medications are not very effective the virus is predominant in the population the virus remains dormant in immune cells the virus replicates extremely slowly

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 therapeutic index is the ratio of the _____ dose to the _____ dose.

toxic therapeutic

The therapeutic index is the ratio of the _____. Multiple choice question. toxic dose to lytic dose toxic dose to therapeutic dose lytic dose to therapeutic dose therapeutic dose to toxic dose

toxic dose to therapeutic dose

The acronym "VRE" stands for -_____ resistant enterococci.

vancomycin

Match each effect with the correct definition. 1. cidal 2. static a. kills the target b. reversibly inhibits the growth of the target

1. a. kills the target 2. b. reversibly inhibits the growth of the target

Match each mechanism of bacterial resistance to antibiotics with the best description. 1. alteration of target 2. alternate pathways 3. drug inactivation 4. efflux pumps a. terminal D-alanine in peptidoglycan changes to D-lactate b. hydrolysis of beta-lactam ring by beta-lactamase c. antiport mechanism where protons enter cell as drugs leave d. use of preformed folic acid, rather than synthesis

1. a. terminal D-alanine in peptidoglycan changes to D-lactate 2. d. use of preformed folic acid, rather than synthesis 3. b. hydrolysis of beta-lactam ring by beta-lactamase 4. c. antiport mechanism where protons enter cell as drugs leave

Match each antibiotic with its mechanism of action. 1. aminoglycosides 2. macrolides 3. oxazolidinones a. prevent formation of the 70S initiation complex b. bind to the 50S ribosomal subunit c. bind to the 30S ribosomal subunit

1. c. bind to the 30S ribosomal subunit 2. b. bind to the 50S ribosomal subunit 3. a. prevent formation of the 70S initiation complex

The antimicrobial activity of the tetracycline family of antibiotics results from their binding to _______. Multiple choice question. RNA polymerase messenger RNA topoisomerase 30S ribosomal subunit 50S ribosomal subunit

30S ribosomal subunit

Macrolide antibiotics interfere with protein synthesis by binding to _____. Multiple choice question. DNA polymerase ATP synthase 50S ribosomal subunit 30S ribosomal subunit

50S ribosomal subunit

This image illustrates the _____ to determine antibiotic susceptibility and MIC. Kirby-Bauer disk diffusion Etest static/cidal

Etest

Which of the following conditions has a significant contribution to the maintenance of drug resistant genes in a bacterial population? Multiple choice question. Exposure of bacteria to ultraviolet radiation Formation of biofilms Exposure of bacteria to the drug Immune deficiencies of the host

Exposure of bacteria to the drug

Why are there fewer antifungal drugs than antibacterial drugs? Multiple choice question. Fungal infections are rare and non-life threatening. Fungal cells are more similar to human cells than bacterial cells. Bacterial cells are more similar to human cells than fungal cells.

Fungal cells are more similar to human cells than bacterial cells.

Which two of the following characteristics do not apply to macrolide antibiotics? Multiple select question. Has a four ring structure Is a broad spectrum antibiotic Inhibits DNA replication Is usually bacteriostatic

Has a four ring structure Inhibits DNA replication

Which two of the following characteristics apply to aminoglycosides? Multiple select question. Synthesis of abnormal proteins Often a drug of last resort Inhibit gyrase activity Bind to 30S ribosomal subunit Inhibit cell wall synthesis

Synthesis of abnormal proteins Bind to 30S ribosomal subunit

Which type of fungal infection is the most likely to be fatal? Multiple choice question. Subcutaneous Systemic Superficial

Systemic

Which two of the following are examples of superficial mycoses? Multiple select question. Cryptococcal meningitis Toenail fungus Mycoplasma pneumoniae Oral candidiasis (thrush) Coccidioidomycosis

Toenail fungus Oral candidiasis (thrush)

Which two of the following statements regarding artemisinin are correct? Multiple select question. a. Artemisinin originally derived from traditional Chinese medicine. b. Artemisinin is a semisynthetic derivative of chloroquine. c. A semisynthetic artemisinin is an effective, inexpensive treatment for malaria. d. Artemisinin was originally extracted from green tea leaves.

a. Artemisinin originally derived from traditional Chinese medicine. c. A semisynthetic artemisinin is an effective, inexpensive treatment for malaria.

Which three of the following are believed to be mechanisms of action of penicillin? Multiple select question. a. inhibit the transpeptidation reaction in peptidoglycan synthesis b. activate cellular nucleases to hydrolyze the chromosome c. inhibit the active site of topoisomerases d. bind to the ribosomal P site to halt translation e. stimulate holins to form holes in the plasma membrane f. activate bacterial autolytic enzymes

a. inhibit the transpeptidation reaction in peptidoglycan synthesis e. stimulate holins to form holes in the plasma membrane f. activate bacterial autolytic enzymes

Lincosamine antibiotics have a broad spectrum of activity against _____. Multiple choice question. aerobes Gram negatives anaerobes psychrophiles

anaerobes

A substance that blocks the functioning of a specific biochemical pathway is called a(n) _____. Multiple choice question. antimicrobial antibody coenzyme antimetabolite

antimetabolite

A(n) _____ is an antimicrobial substance that antagonizes or blocks the function of a specific biochemical pathway.

antimetabolite

The antimalarial drug _____ has its origins in traditional Chinese medicine, and is now an effective and inexpensive treatment. Multiple choice question. artemisinin griseofulvin primaquine dapsone

artemisinin

The highest therapeutic index is found with antimicrobial drugs that target _____ _____ synthesis.

cell wall

The most selective antibiotics target _____. Multiple choice question. cell wall synthesis nucleic acid synthesis protein synthesis metabolic pathways

cell wall synthesis

All aminoglycoside antibiotics contain a(n) _____ ring and amino sugars.

cyclohexane

The aminoglycoside antibiotics are characterized by the presence of amino sugars and a _____. Multiple choice question. lactone ring cyclohexane ring β-lactam ring four ring structure

cyclohexane ring

A clear area that forms around an antibiotic disk after incubation with a bacterial strain is called a _____ of inhibition.

zone

The structural component of the penicillin molecule that is critical for antimicrobial activity is the _______. Multiple choice question. lactone ring β-pleated sheet β-lactam ring cyclohexane ring

β-lactam ring

The basis of penicillin resistance in bacteria is the ability to produce enzymes called penicillinases or _______. Multiple choice question. β-lactamases acetyltransferases aminoglycosides α-amylases

β-lactamases