Chapter 12 objectives Flashcards
All of the following pertain to cephalosporins except:
newer generations have activity against gram-negative bacteria.
many administered by injection, not orally.
have a beta-lactam ring.
are synthetic drugs.
are synthetic drugs
Which of these drugs has the most narrow-spectrum activity?
aminoglycosides
isoniazid
erythromycin
cephalosporins
isoniazid
The drug used against intestinal anaerobic bacteria, that can also alter normal biota leading to antibiotic-associated colitis, is
clindamycin.
ciprofloxacin.
gentamicin.
chloramphenicol.
clindamycin.
Each of the following effect cell walls except
erythromycin.
vancomycin.
penicillin.
cycloserine.
erythromycin.
Mebendazole, thiabendazole, and ivermectin are drugs used to treat _____ infections.
fungal
helminthic
bacterial
protozoan
helminthic
Which of the following microbials does not inhibit DNA synthesis?
chloroquine
quinolone
penicillin
acyclovir
penicillin
Nutrients that encourage the growth of beneficial microbes in the intestines are known as:
probiotics.
prebiotics.
riboswitches.
phytobiotics.
prebiotics.
What type of chemical will allow some bacteria to be resistant to many penicillins?
aztreonam
synercid
penicillinase
imipenem
penicillinase
The drug used for several protozoan infections is
metronidazole.
sulfa drugs.
griseofulvin.
amphotericin B.
metronidazole.
A superinfection results from:
a decrease in most normal biota resulting in the overgrowth of an unaffected species.
build up of a drug to toxic levels in the patient.
an immune system reaction to the drug.
the wrong drug administered to the patient.
a decrease in most normal biota resulting in the overgrowth of an unaffected species.
Each of the following is a mechanism for drug resistance transfer between microorganisms except
R-plasmids.
mutation.
conjugation.
mutation.
Substances that are naturally produced by certain microorganisms that can inhibit or destroy bacteria are called
synthetic drugs.
antibiotics.
semisynthetic drugs.
antibiotics.
Microbial resistance resulting from mutation occurs because
All of the choices are correct.
prokaryotic genomes undergo mutation rapidly.
prokaryotic genomes undergo mutation often.
mutations are passed between organisms.
short generation times accumulate mutations in populations.
All of the choices are correct.
The use of a drug to prevent imminent infection is called
synergism.
prebiotics.
prophylaxis.
prophylaxis
It is better to use a broad-spectrum drug instead of a more specific, narrow-spectrum drug.
False
True
False
You have given a dosage of an antibiotic to a patient for his infection, but the patient is not getting any better. The MIC tests shows that the drug that you prescribed, at the dosage that was given, should work against this particular strain of bacterium. What do you think might be the problem?
The patient is resistant to the drug.
The bacterium is immune to the chemical effects of the drug.
The drug might be broken down in the patient’s body before it can have its full effect on the bacterium.
The drug might be broken down in the patient’s body before it can have its full effect on the bacterium.
The Kirby-Bauer test uses an agar surface, seeded with the test bacterium, to which small discs containing a specific concentration of several drugs are placed on the surface.
False
True
True
Drugs that insert on the _____ ribosomal subunit prevent peptide bond formation or inhibit translocation of the subunit during translation.
70S
60S
50S
40S
50S
The antifungal drug that can be used to treat serious systemic fungal infections is
metronidazole.
griseofulvin.
amphotericin B.
amphotericin B.
Broad-spectrum drugs that disrupt the body’s normal biota often cause
nephrotoxicity.
superinfections.
allergic reactions.
superinfections.
The cellular basis for bacterial resistance to antimicrobials include
synthesis of enzymes that alter drug structure.
All of the choices are correct.
alteration of drug receptors on cell targets.
prevention of drug entry into the cell.
bacterial chromosomal mutations.
All of the choices are correct.
Alexander Fleming had been running tests using Staphylococcus, and left some plates out to incubate. Evidently, after returning to his lab after the weekend, he found that Penicillium mold was growing on his agar plates containing the growth of Staphylococcus. Looking more closely, he found a large, clear area around the mold colony where Staphylococcus colonies did not grow. Given this situation, a valid hypothesis would be that:
The Penicillium mold was being killed by the Staphylococcus.
The bacteriological medium being used in the plates was somehow inhibitory to the Staphylococcus growth.
The Staphylococcus was being inhibited by the Penicillium mold.
The Staphylococcus was being inhibited by the Penicillium mold.
Which antimicrobial does not inhibit cell wall synthesis?
cephalosporins
penicillins
gentamicin
gentamicin
Over 50 percent of all sales of medically important antibiotics in the United States are for livestock use. Why is this problematic for humans?
Resistant bacteria grow in the animals and may then be passed to humans.
The animals may become sick from the antibiotic ingestion.
The livestock will become resistant to the antibiotics and not respond to treatment when they have infections.
Resistant bacteria grow in the animals and may then be passed to humans.
Bacteria can have a natural resistance to a drug which they have never been exposed.
False
True
True
Side effects that occur in patient tissues while they are on antimicrobial drugs include all of the following except
hepatotoxicity.
diarrhea.
deafness.
development of resistance to the drug.
development of resistance to the drug.
In a conversation with your friends from microbiology class, you are talking about drug resistance. The three of you disagree about the definition of the term so each of you state his or her definition and give a justification. Compare the various definitions and justifications below and pick the one that is most accurate.
The person becomes resistant to the drug: The body adjusts to the dosage of the chemical and no longer responds to its action.
The drug is changed in the body and is inactivated physically and chemically so it no longer works properly against the bacterium.
The bacterium has changed physically or chemically in some way to be able to destroy the drug or avoid its action, allowing it to grow unimpeded by the drug.
The bacterium has changed physically or chemically in some way to be able to destroy the drug or avoid its action, allowing it to grow unimpeded by the drug.
Which of the following is not used to treat malaria?
primaquine
metronidazole
meflaquine
metronidazole
Primaquine and chloroquine are drugs used in the treatment of ___ infections.
protozoan
gram-positive bacterial
fungal
protozoan
Drug susceptibility testing determines:
the patient’s response to various antimicrobials.
if the drug is increasing to toxic levels in a patient.
the pathogen’s response to various antimicrobials.
the pathogen’s response to various antimicrobials.
An ideal antimicrobial therapeutic drug exhibits all of the following characteristics except
nontoxic to host.
easily broken down by host.
easily administered.
easily broken down by host.
Antibiotics which disrupt prokaryotic ribosomes can also affect
eukaryotic small ribosomal subunit.
eukaryotic large ribosomal subunit.
eukaryotic mitochondrial ribosomes.
eukaryotic mitochondrial ribosomes.
Which antibiotic is used to treat MRSA and VRE infections?
azithromycin
linezolid
synercid
linezolid
Antibiotics are derived from all of the following except:
Cephalosporium.
Staphylococcus.
Bacillus.
Staphylococcus.
Infections caused by gram-negative bacilli are often treated with
aminoglycosides.
penicillin G.
synercid.
aminoglycosides.
Indwelling catheter biofilm infections are more resistant to antibiotics than nonbiofilm infections.
False
True
True
Which of the following is not a drug group used to treat fungal infections?
quinolones
macrolide polyene antibiotics
flucytosine
quinolones
What antibiotic is mixed with neomycin and polymyxin to make an antibiotic ointment (Neosporin) for superficial skin infections?
streptomycin
bacitracin
chloramphenicol
bacitracin
Which antimicrobial does not interfere with protein synthesis?
chloramphenicol
erythromycin
trimethroprim
trimethroprim
Ampicillin, amoxicillin, mezlocillin, and penicillin G all have
a semisynthetic nature.
an expanded spectrum of activity.
a beta-lactam ring.
a beta-lactam ring.
An antiviral that is a guanine analog would have an antiviral mode of action that
bonds to ergosterol in the cell membrane.
inhibits DNA synthesis.
blocks penetration.
inhibits DNA synthesis.
Your patient has been on antibiotics for 6 weeks after a case of streptococcal endocarditis, an infection of the inner heart wall. The infection clears up. However, the patient just visited you about a urinary tract infection, and the lab verified that the culprit was E. coli. What do you hypothesize happened in this situation?
Her normal microbiota in the genitourinary tract were killed, allowing E. coli (not killed by the antibiotics) to establish an infection.
The lab has made a mistake in identifying the cause, and, in fact, the endocarditis was caused by the E. coli.
The antibiotics damaged her immune system, making her very susceptible to environmental bacteria.
Her normal microbiota in the genitourinary tract were killed, allowing E. coli (not killed by the antibiotics) to establish an infection.
Sulfonamides are analogs of PABA and, as a result, they inhibit _____ synthesis.
phospholipid
folic acid
protein
folic acid
Penicillins and cephalosporins
interfere with elongation of peptidoglycan.
are metabolic analogs of PABA and block folic acid synthesis.
block peptidases that cross-link glycan molecules.
block peptidases that cross-link glycan molecules.
There are fewer antifungal, antiprotozoan, and antihelminthic drugs compared to antibacterial drugs because fungi, protozoa, and helminths
do not cause many human infections.
are so similar to human cells that drug selective toxicity is difficult to achieve.
fewer target sites in their cells compared to bacteria.
are so similar to human cells that drug selective toxicity is difficult to achieve.
A chemical that inhibits beta-lactamase enzymes is:
aztreonam.
clavulanic acid.
synercid.
clavulanic acid.
Sulfa drugs work on
folic acid biosynthesis.
nucleic acid biosynthesis.
ribosome biosynthesis.
folic acid biosynthesis.
Antiviral drugs that target reverse transcriptase would be used to treat infections caused by:
HIV.
influenza A virus.
hepatitis C virus.
HIV.
The use of vaginal inserts of Lactobacillus to restore a healthy acidic environment is an example of
prebiotics.
probiotics.
phytobiotics.
probiotics.
Drugs that are hepatotoxic cause damage to a patient’s kidneys.
False
True
False
Sulfonamides
are metabolic analogs of PABA and block folic acid synthesis.
interfere with elongation of peptidoglycan.
block peptidases that cross-link glycan molecules.
are metabolic analogs of PABA and block folic acid synthesis.
Aminoglycosides:
damage cell membranes.
are metabolic analogs of PABA and block folic acid synthesis.
attach to the 30S ribosomal subunit and disrupt protein synthesis.
attach to the 30S ribosomal subunit and disrupt protein synthesis.
If pathogen A is more resistant to an erythromycin disc on a Kirby-Bauer plate compared to pathogen B, then pathogen A will have a/n _____ zone of inhibition compared to pathogen B.
equal
smaller
larger
smaller
Resistance genes can be transferred to other bacterial cells during transformation, transduction, and conjugation.
False
True
True
The multidrug resistant pumps in many bacterial cell membranes function by
bacterial chromosomal mutations.
removing the drug from the cell when it enters.
synthesis of enzymes that alter drug structure.
removing the drug from the cell when it enters.
Which drug is used to treat cases of tuberculosis?
tetracycline
isoniazid
penicillin G
isoniazid
The _____ are drugs that deposit in developing teeth and cause a permanent brown discoloration.
streptomycins
tetracyclines
penicillins
tetracyclines
Who is considered to be the father of modern antibiotics?
Crick
Fleming
Chargaff
Fleming
Acyclovir is used to treat infections caused by:
hepatitis C virus.
herpes simplex virus.
influenza A virus.
herpes simplex virus.
The use of any chemical in the treatment, relief, or prophylaxis of a disease is called
nephrotoxicity.
selective toxicity.
chemotherapy.
chemotherapy.
Important characteristics of antimicrobial drugs include
do not cause serious side effects in humans.
All of the choices are correct.
low toxicity for human tissues.
high toxicity against microbial cells.
stable and soluble in body tissues and fluids.
All of the choices are correct.
What drug is used in cases of penicillin and methicillin resistance and also used to treat endocarditis?
isoniazid
erythromycin
vancomycin
vancomycin
Which of the following antibacterial drug groups does not target protein synthesis?
macrolides
aminoglycosides
sulfonamides
sulfonamides
A ratio of the dose of the drug that is toxic to humans versus the minimum effective dose for that pathogen is assessed to predict the potential for toxic drug reactions. This is called the:
Kirby-Bauer technique.
therapeutic index (TI).
antibiogram.
therapeutic index (TI).
An antibiotic of the penicillin family is penicillin G.
False
True
True
All _____ consist of a thiazolidine ring, a beta-lactam ring, and an R group.
aminoglycosides
penicillins
tetracyclines
penicillins
Each of the following target prokaryotic ribosomes except:
streptomycin.
tetracycline.
polymyxins.
polymyxins.
