Smartbook CH. 12 Flashcards
1
Q
_____ chemotherapy is the use of chemotherapeutic drugs to control infections and diseases caused by many types of microorganisms.
A
antimicrobial
2
Q
Which of the following are characteristics of an ideal antimicrobial drug?
A
Inexpensive
Longevity
Selective toxicity to infecting agent
Microbicidal
3
Q
True or false: Microorganisms that produce antibiotics in their natural habitat may have a selective advantage over neighboring microbes.
A
true
4
Q
Antibiotics are made primarily by aerobic spore-forming _____ and _____.
A
bacteria and fungi
5
Q
What is the term for an antimicrobial drug that is chemically synthesized in the laboratory?
A
synthetic
6
Q
What is the overall goal of antimicrobial chemotherapy?
A
To destroy the infective agent without harming the patient
7
Q
Which of the following is an antimicrobial drug isolated from natural sources and then chemically modified in the laboratory?
A
semisynthetic
8
Q
Which of the following is a substance produced by natural metabolic processes of some microorganisms that can inhibit or kill other microorganisms?
A
antibiotic
9
Q
The use of a drug to prevent imminent infection of a person at risk is called which of the following?
A
Prophylaxis
10
Q
A great number of antibiotics are derived from which of the following bacterial genera?
A
Streptomyces
Bacillus
11
Q
The property of an antimicrobial agent to be highly toxic against its target microbe while being far less toxic to the cells of the host organism is called
A
selective toxicity
12
Q
Which of the following are synthetic antimicrobial drugs?
A
Azoles
Quinolones
Quinines
13
Q
Which of the following are primary sites for action of antimicrobial drugs in bacteria?
A
Cell membrane
Nucleic acids
Cell wall
Ribosomes
14
Q
Bacitracin is an antibiotic with which spectra of activity?
A
narrow
15
Q
The most common approach to drug production is the _____ method, which combines both natural and synthetic methods.
A
semisynthetic
16
Q
Which of the following occurs when antibiotics interact in ways that enhance or magnify each other?
A
Synergism
17
Q
The cell walls of most bacteria are composed primarily of which of the following?
A
Peptidoglycan
18
Q
Which of the following is an example of drug that blocks bacterial cell wall synthesis and exhibits excellent selective toxicity?
A
Penicillin
19
Q
Which bacteria are the most susceptible to antibiotics that target the cell wall?
A
Young, growing
20
Q
Primary site for action of antimicrobial drugs in bacteria?
A
Nucleic acids
Cell wall
Cell membrane
Ribosomes
21
Q
Which of the following antibiotics inhibit bacterial cell wall synthesis?
A
Ampicillin
Cycloserine
Vancomycin
22
Q
Tetracycline is an example of which type of drug?
A
Broad spectrum
23
Q
True or false: Damage to the bacterial cell membrane can disrupt metabolism or lyse the cell.
A
TRUE
24
Q
Which of the following structures in bacteria protect the cell from lysis (rupture) in hypotonic environments?
A
Cell wall
25
Antibiotics that disrupt nucleic acid synthesis do so by targeting components of which processes?
DNA replication
Transcription
26
Which of the following is the consequence of exposure of a bacterium to an antibiotic that inhibits cell wall synthesis?
Cell lysis
27
Which of the following are primary sites for action of antimicrobial drugs in bacteria?
Ribosomes
Nucleic acids
Cell membrane
Cell wall
28
Cell wall inhibitors like penicillins and cephalosporins interfere with enzymes responsible for which of the following?
Cell wall construction
29
Antimicrobial drugs that damage cell membrane function usually do so by creating leaks in the membrane that disrupt which of the following?
Cell metabolism
Osmotic tolerance
30
Protein synthesis inhibiting drugs affect the activity of which of the following?
Ribosomes
31
The broad-spectrum quinolones inhibit which of the following?
Helicase
32
Antimicrobial drugs interfere with nucleic acid synthesis by blocking synthesis of nucleotides, inhibiting replication, or stopping transcription.
32
Antimicrobial drugs interfere with nucleic acid synthesis by blocking synthesis of nucleotides, inhibiting replication, or stopping transcription.
33
The broad-spectrum quinolones inhibit DNA-unwinding enzymes or helicases, thereby stopping DNA replication and repair.
34
Which type of inhibition of an enzyme occurs when the enzyme is blocked from action after a substance that mimics the normal substrate binds to the active site?
Competitive
35
Sulfonamides compete with
_____ for the active site of the enzyme that synthesizes the folic acid precursor.
PABA
36
Antimicrobial drugs that block bacterial protein synthesis could also affect which of the following in the host cell?
Eukaryotic mitochondria
37
One potential therapeutic consequence of drugs that bind to the prokaryotic ribosomes is the damage they can do to eukaryotic mitochondria.
38
Which of the following antibiotics contain the beta-lactam ring?
Penicillins
Cephalosporins
39
_____ analogs are structurally similar to the natural substrate and compete with it for the active site on the enzyme.
metabolic
40
Which of the following is a natural fermentation product of Penicillin chrysogenum?
Penicillin G
41
Which of the following interfere with folate metabolism?
Sulfonamides
Trimethoprim
42
_____ penicillins are drugs that, after being naturally produced by bacteria, are chemically modified in the laboratory.
semisynthetic
43
Cell wall inhibitors like penicillins and cephalosporins interfere with enzymes responsible for which of the following?
Cell wall construction
44
Which of the following semisynthetic penicillins are useful in treating infections caused by penicillinase-producing bacteria?
Nafcillin
Cloxacillin
45
Identify the active part of the penicillin structure.
Beta-lactam ring
46
Patients taking penicillin may experience ________
allergic reactions
47
____ ____ serves as the parent compound for all "-cillin" drugs..
Penicillin G
48
Isoniazid works by interfering with the synthesis of _______
mycolic acid
49
Which two semisynthetic penicillins can be used against Gram-negative bacteria?
Amoxicillin
Ampicillin
50
The tetracyclines bind to which of the following structures?
Ribosome
51
Which of the following enzymes secreted by certain bacteria cleaves the beta-lactam ring of penicillins and provides for resistance against the antibiotic?
Beta-lactamase
Penicillinase
52
Which of the following diseases can be treated with tetracyclines such as doxycycline and minocycline?
Rocky Mountain spotted fever
Cholera
Mycoplasma pneumonia
53
Antimicrobial drugs that block bacterial protein synthesis could also affect which of the following in the host cell?
Eukaryotic mitochondria
54
The staining of teeth is one side effect of the antibiotic group known as the
tetracyclines
55
Two major problems for treatment with penicillin are that some patients experience which of the following?
Resistant strains of pathogens
Allergic responses
56
Griseofulvin is which type of agent?
Antifungal
57
Which two of the following antibiotics are used to treat tuberculosis?
Ethambutol
Isoniazid
58
Which of the following was the principal treatment for malaria for hundreds of years?
Quinine
59
Tetracyclines inhibit __________ ?
Protein synthesis
60
Which of the following drugs are currently in use against Plasmodium infections?
Chloroquine
Primaquine
61
Which tetracycline is being used in hospitals to treat MRSA infections?
Tigecycline
62
Metronidazole is classified as which type of agent?
Amoebicide
63
What is a major side effect of tetracyclines?
Deposition in hard tissues
64
Drugs that are effective against fungi have a strong possibility of being toxic to humans because both organisms are which of the following?
Eukaryotes
65
The most effective drugs that treat infections caused by flukes, tapeworms, and roundworms typically block metabolism at all stages of the life cycle rather than eradicate the adult worms.
66
The bark of the Cinchona tree is used to make
quinine
67
In recent years quinine has been replaced in the treatment of malaria by drugs in which of the following categories?
Quinolines
68
True or false: Antiviral drugs prevent penetration into a host cell, block transcription and translation, and prevent maturation of viral particles.
True
69
Antiviral drugs prevent the replication of viral particles.
70
Metronidazole is used to treat which of the following protozoan pathogens?
Giardia lamblia
Trichomonas vaginalis
Entamoeba histolytica
71
Reverse transcriptase is a retroviral enzyme that does which of the following?
Converts RNA to DNA
72
The staining of teeth is one side effect of the antibiotic group known as the
tetracyclines
73
What type of RNA virus can use its RNA as a template to produce DNA?
Retrovirus
74
The most effective drugs used to treat infections caused by flukes, tapeworms, and roundworms inhibit _______ at all stages of the life cycle rather than eradicating the adult worms.
metabolism
75
Interferon is produced primarily by
fibroblasts
leukocytes
76
Identify the three major modes of action of antiviral drugs.
Barring virus penetration into host cell
Blocking virus transcription and translation
Preventing virus maturation
77
The tolerance of an antimicrobial agent at a level which would normally be inhibitory is called which of the following?
Drug resistance
78
A viral enzyme that converts single-stranded RNA into double-stranded DNA is called
reverse transcriptase
79
Any RNA virus that can convert its own RNA into double-stranded DNA is called a(n)
retrovirus
80
Drug resistance occurs with spontaneous ______ or gene transfer from another species.
mutations
81
A resistance factor is a _______ that confers drug resistance and is often shared among bacteria by conjugation.
plasmid
82
Which of the following is a normal human glycoprotein produced in response to immune stimuli and can be used therapeutically to fight viruses and cancer?
Interferon
83
Organisms resistant to penicillins and _________ often produce beta-lactamases that hydrolyze the beta-lactam ring structure of the antibiotic.
cephalosporins
84
The outer membrane of some Gram- ______ bacteria act as natural barriers to some drugs.
gram-negative
85
One mechanism by which microbes can become resistant to a drug is to produce a(n) _____ that alters the structure of the drug.
enzyme
86
Resistance to aminoglycosides can result from changes in cell permeability caused by mutations in proteins in which of the following?
Transport system
Outer membrane
87
Drug resistance arises from
an organism gaining the genetic information for the resistance from another organism
from a spontaneous mutation within the chromosomes
88
Which is the mechanism used by multidrug-resistant (MDR) pumps to expel antimicrobial drugs and other toxic substances from a bacterial cell?
Proton-motive force similar to ATP synthesis
89
Resistance factors are shared among bacteria by which of the following processes?
Conjugation
Transformation
Transduction
90
Erythromycin and clindamycin resistance is associated with an alteration of the drugs target on the organism's __________.
50S ribosomal subunit
91
The production of beta-lactamases is responsible for which of the following?
Drug inactivation
92
Resistance to which of the following drugs develops when microbes deviate from the usual pathway that leads to the production of folic acid?
Trimethoprim
Sulfonamides
93
Microbes can inactivate drugs by producing which of the following that change the structure of the drug to a nontoxic form?
Enzymes
94
Bacteria that form ______ are difficult to control because the buildup of cells makes it difficult to for the antibiotic to reach a majority of the cells.
biofilms
95
The _____ _____ of the cell wall of certain gram-negative bacteria is a natural blockade against some penicillin derivatives.
outer membrane
96
Which term describes the process of some microbes dying while others live in the presence of antimicrobial agents?
Natural selection
97
Many bacteria possess multidrug-resistant (MDR) _____ that actively transport drugs and other chemicals out of cells.
pumps
98
Drug _____ of microbes to specific drugs can increase as a result of genetic based changes in the target site (receptor) that the drug binds to.
resistance
99
The use of two or more drugs to treat one infection or disease is called
combination therapy
100
Resistance to sulfonamides and trimethoprim develops when microbes use an alternative pathway for _____ acid synthesis.
folic
101
Which of the following is not a side effect associated with antimicrobial drugs?
Host cell metabolism of drug
102
Biofilms are best known to do which of the following?
Reduce drug efficacy
103
An allergy is caused by a hypersensitive response from which system?
Immune
104
Natural selection for drug-resistant forms of bacteria is common
105
Use of which type of antibiotic can have far reaching affects on beneficial resident species?
Broad-spectrum
106
Which of the following are strategies that can help limit drug resistance of microorganisms?
Physicians should prescribe antibiotics carefully by choosing narrow-spectrum agents when possible
Research should focus on developing shorter term, higher-dose antibiotics
Patients must comply with physicians guidelines when taking antibiotics
107
One approach to deal with microbes known to be drug resistant is to do which of the following?
Combined therapies
108
Which of the following are side effects associated with antimicrobial drugs?
Disruption of normal microflora
Allergic reactions
Damage to host tissues due to toxicity
109
When antimicrobial therapy destroys beneficial resident microbes and allows an overgrowth of drug-resistant microorganisms, it is called which of the following?
Superinfection
110
_____ sp. can cause superinfections of the oropharynx called thrush.
Candida
111
Which of the following are known to cause superinfections?
Tetracyclines
Cephalosporin
Clindamycin
112
True or false: The nature and sensitivity of the microorganism need to be considered before antimicrobial treatment begins.
true
113
Which of the following is not a side effect associated with antimicrobial drugs?
Host cell metabolism of drug
114
A side effect associated with antimicrobial drugs?
Disruption of normal microflora
Damage to host tissues due to toxicity
Allergic reactions
115
Direct examination of body fluids, sputum, and stool can provide a rapid detection method for which of the following?
Bacteria
Fungi
116
When a broad-spectrum cephalosporin antibiotic is given to a patient with a UTI infection caused by E. coli, one possible side effect is a vaginal infection caused by which fungus?
Candida albicans
117
Which of the following bacteria are normally not tested for drug susceptibility?
Group A streptococci
118
Antibiotic-associated colitis is caused by which of the following bacteria?
Clostridium difficile
119
The Kirby-Bauer technique is not recommended for which bacterium?
Mycobacterium sp.
120
Which of the following are the three factors that should be known before selecting an antimicrobial drug?
The overall health of the patient
The nature of the infecting agent
The sensitivity of the infecting agent
121
_____ is an agar diffusion test that can be used on anaerobes, mycobacteria, and fungi.
Etest
122
If the bacterium causing a sore throat is Streptococcus pyogenes, a physician can normally prescribe the antibiotic,
penicillin
123
True or false: The Etest can be used to quantify developing resistance of a particular organism to an antibiotic.
true
124
Which of the following bacteria are routinely tested for drug susceptibility?
Staphylococcus sp.
Enterococcus faecalis
Aerobic Gram-negative enteric bacilli
125
Which of the following involves serially diluting an antibiotic in order to determine the susceptibility of a test bacterium to the drug?
Tube dilution
126
Which of the following techniques is an agar diffusion test to determine antibiotic susceptibility of a particular bacterial strain?
Kirby-Bauer
127
The inability of a drug to _____ into a body compartment, such as the brain or joints, will render the drug ineffective.
diffuse
128
Which of the following TIs would be the riskier choice?
1.1
129
Which of the following is an agar diffusion test that utilizes gradients of antibiotics on strips?
Etest
130
Kirby-Bauer uses antibiotic disks.
131
Antacids reduce the absorption of which drug?
Isoniazid
132
The Etest uses a(n) ______ gradient.
ANTIBIOTIC
133
MIC is the acronym for
minimum inhibitory concentration
134
Drug therapy may fail because the infection is caused by a(n) _____ culture (more than one species).
mixed
135
Which of the following is the ratio of the toxic dose to the effective dose that is used to assess the safety and reliability of the drug?
Therapeutic index
136
Which groups of people may have greater risks to antimicrobials?
Elderly
Pregnant women
Infants
137
When these two drugs are used in combination nephrotoxic effects are increased.
Aminoglycosides
Cephalosporins
138
The type of antimicrobial resistance that is of most concern today:
acquired
139
Synercid binds to sites on the 50S ribosomal subunit. Synercid interferes with
