Test Bank 3 Flashcards
(231 cards)
1
Q
Pathogenicity is the ability
A
of the pathogen to inflict damage on the host.
2
Q
Which of the following is NOT a subunit of lipopolysaccharide (LPS)?
A
M protein.
3
Q
Staphylococcus aureus and Streptococcus pyogenes strains can produce that cause the severe and sometimes life-threatening symptoms of toxic shock syndrome.
A
Superantigen toxins.
4
Q
Diptheria toxin is a
A
AB toxin.
5
Q
Decalcification of the tooth enamel is caused by
A
Lactic acid.
6
Q
The following bacterial genera are all implicated in dental caries EXCEPT
A
Borrelia.
7
Q
Tetanus toxin causes
A
Muscles to be unable to relax.
8
Q
Shiga toxin is an enterotoxin that is produced by
A
Shigella dysenteriae.
9
Q
Exotoxins are ___, but endotoxins are ___.
A
Proteins / lipopolysaccharide-lipoprotein complexes.
10
Q
An endogenous pyrogen is
A
A chemical produced by a host’s own immune system that causes fever.
11
Q
Staphylococcus aureus produces ___, leading to fibrin clots that protect them from attack by host cells.
A
Coagulase.
12
Q
Compared with an endotoxin, would a bacterial exotoxin generally be more likely to function after it had been significantly heated?
A
No, because exotoxins are heat-labile and less resistant to heating than endotoxins.
13
Q
The α-toxin of Clostridium perfringens is
A
A lecithinase.
14
Q
Which of the following hemolysins is a phospholipase?
A
Lecithinase.
15
Q
Salmonella species use ___ to facilitate attachment to gastrointestinal tissue.
A
Type I fimbriae.
16
Q
Influenza virus targets
A
Respiratory epithelium.
17
Q
An outer coat consisting of a dense, well-defined polymer layer surrounding a cell and used in attachment is called a
A
Capsule.
18
Q
Capsules are particularly important for
A
Protecting bacteria from host defense mechanisms.
19
Q
The decrease or loss of virulence of a pathogen is referred to as
A
Attenuation.
20
Q
It is thought that attenuation occurs especially in a laboratory setting because
A
Nonvirulent or weakly virulent mutants grow faster in laboratory media when there is no selective advantage to virulence.
21
Q
Which disease CANNOT be prevented via the use of a vaccine generated from an attenuated pathogen?
A
Malaria.
22
Q
Which of the following is NOT important for the adherence of bacteria to host tissues?
A
Lipopolysaccharides.
23
Q
Which of the following is an important factor in the development of dental caries?
A
High sugar diet.
24
Q
The spread of pathogens through the blood and lymph systems that results in a bloodborne systemic infection is called
A
Septicemia.
25
Which genus produces hyaluronidase?
Streptococcus.
26
Which of the following is more likely to cause urinary tract infections?
Fimbriated strains of Escherichia coli.
27
Which of the following is NOT an example of an AB toxin?
Hemolysins.
28
Which of the following does NOT affect pathogen growth?
All of these answer choices affect growth.
29
Siderophores are
Organic molecules that help pathogens take up iron.
30
Cytolytic toxins
Are extracellular proteins that cause cell lysis and death by damaging the host cytoplasmic membrane.
31
Which of the following is a reason that specific pathogens tend to infect specific tissues?
Some tissues have receptors for microbes, but others do not.
32
The collective term for the organisms living on or in the human body, as opposed to a general term for organisms in an environmental habitat, is
The human microbiome.
33
___ in saliva cleaves glycosidic linkages in the peptidoglycan that is present in bacterial cell walls, weakening the wall and potentially causing cell lysis.
Lysozyme.
34
Which of the following is a way to prevent attenuation and maintain virulence in a bacterium?
Inoculating an animal with the bacterium.
35
Which of the following is TRUE about flagella?
They may be involved in adherence to a lesser extent than pili and fimbriae.
36
___ is a damage or injury to a host organism that impairs its function.
Disease.
37
Pathogenicity and virulence differ in that
Pathogenicity refers to the overall ability of a microbe to cause disease, whereas virulence refers to the ability of one microbe to cause disease relative to another.
38
Epithelial cells lining the respiratory tract form a
Mucous membrane.
39
What is the difference between adherence and colonization?
Colonization occurs when a microbe begins to grow in host tissues, whereas adherence occurs when the microbe initially attaches.
40
Which of the following pathogens does NOT use capsules or a slime layer for attachment?
Vibrio cholera.
41
Which of the following is a major growth-limiting micronutrient that influences microbial growth?
Iron.
42
The dose of an antigen that kills 50% of animals in a test group and is used to estimate the virulence of a pathogen is known as
LD50 (lethal dose50).
43
The best term to describe the general process by which microorganisms cause diseases is known as
Pathogenesis.
44
The macromolecules responsible for bacterial adherence that are NOT covalently attached to bacteria are collectively called
Glycocalyx.
45
Septicemia is an example of a
Systemic infection.
46
The process by which white blood cells ingest and kill bacteria is called
Phagocytosis.
47
The condition that results when some bacteria are shed in the bloodstream and distributed to distant parts of the body but do not reproduce in the blood is called
Bacteremia.
48
___ are toxic proteins released from the pathogen during normal growth.
Exotoxins.
49
Which of the following is a category of exotoxin?
Cytolytic toxin.
50
___ are microbial infections acquired by hospital patients with noninfectious diseases because they are compromised hosts.
Healthcare-associated infections.
51
The ability of humans to resist a disease is called
Immunity.
52
Cells that can engulf foreign particles, and can ingest, kill, and digest most bacterial pathogens are called
Phagocytes.
53
Adaptive immunity occurs when
The innate immune response fails to eliminate pathogens in the body and virulent infections persist after the initial innate defense response.
54
Blood and lymph have the following in common EXCEPT
Red blood cells.
55
Stem cells are produced and developed in the
Bone marrow.
56
Which of the following is TRUE about cytokines?
They are proteins that play an important role in immunity and the growth of stem cells.
57
Which of the following cell types has NO nucleus?
Erythrocytes.
58
The secondary lymphoid organs consist of which of the following?
Lymph nodes, MALT, and the spleen.
59
Which of the following can cause allergy symptoms and inflammation by degranulation?
Polymorphonuclear leukocytes.
60
The unique antigen-reactive proteins of T cells are
T cell receptors.
61
The rapid increase in adaptive immunity after a second antigen exposure is called
Immune memory.
62
An example of pathogen-associated molecular patterns (PAMP) is
Lipopolysaccharide (LPS).
63
The process by which antibodies block interactions between pathogens or their products and host cells is termed
Neutralization.
64
Which of the following are molecular mediators of inflammation?
Both chemokines and cytokines.
65
Immunoglobulins are produced by B cells and are also known as
Antibodies.
66
MHC I proteins are found
On all nucleated cells.
67
Enhanced phagocytosis of antibody-sensitized cells is known as
Opsonization.
68
Pattern recognition receptors are most directly used
By phagocytes to detect pathogens.
69
Which of the treatments listed below would be most effective for a patient with severe combined immunodeficiency (SCID)?
Bone marrow transplant.
70
The body's non-inducible, preexisting ability to recognize and destroy a variety of pathogens or their products is called
Innate immunity.
71
Adaptive immune responses are directed at pathogen molecules called
Antigens.
72
The cells active in both innate and adaptive immunity develop from common pluripotent precursors in the bone marrow called
Stem cells.
73
The first defense cells that interact with a pathogen in the body are
Macrophages.
74
The inflammatory cytokines IL-1, IL-6, and TNF-α are also
Capable of producing systemic fever by stimulating the release of prostaglandins in the brain.
75
DiGeorge’s syndrome is a developmental defect that prevents the maturation of the thymus. What cell type would be reduced by this condition?
T cells.
76
Intracellular pathogens sometimes produce ___ that can kill phagocytes.
Leukocidins.
77
C-reactive protein is a
Pattern recognition receptor (PRR).
78
Pattern recognition receptors (PRRs) are found on which of the following cells?
Macrophages and neutrophils.
79
Which of the following interact with toll-like receptors (TLRs)?
Bacterial LPS.
80
Interaction of a pathogen-associated molecular pattern (PAMP) with a pattern recognition receptor (PRR) results in
Transmembrane signal transduction that initiates transcription of genes involved in phagocytosis, inflammation, and pathogen killing.
81
Which of the following are proteins that interact directly with antigens during the adaptive immune response?
All of these (immunoglobulins, T cell receptors, MHC proteins).
82
Communication between cells of the immune system is accomplished in many cases through
Cytokines.
83
Chemokines are a group of small proteins that
Function as chemoattractants for phagocytes and lymphocytes.
84
The PAMP recognized by mannose-binding lectin (MBL) is the sugar mannose, found as a repeating subunit in
Bacterial polysaccharides.
85
Which of the following is a likely target for a toll-like receptor (TLR)?
Flagellin.
86
Interaction of a PAMP with a TLR triggers transmembrane signal transduction and subsequent
Phagocytosis and inflammation.
87
Signal transduction pathways initiate activation of transcription after specific
Ligand-receptor binding on the cell surface.
88
Some of the cytokines produced by lymphocytes are called
Interleukins.
89
Fever is induced at the systemic level by ___, which is an endogenous pyrogen.
IL-6.
90
The primary function of a phagocyte is to
Both engulf and destroy pathogens.
91
Which of the following are NOT phagocytes?
Erythrocytes.
92
Which of the following is a function of dendritic cells?
Both phagocytosis and antigen presentation.
93
Phagocytes have a pathogen-recognition system known as ___ that leads to the recognition, containment, and destruction of a pathogen.
Pattern recognition receptors (PRRs).
94
Oxygen compounds toxic to pathogens include
Hydrogen peroxide, hypochlorous acid, and nitric oxide.
95
The enhancement of phagocytosis due to deposition of antibody on the surface of a pathogen or antigen is called
Opsonization.
96
___ are cytotoxins produced by T cells that cause apoptosis.
Granzymes.
97
Another name for 'programmed cell death' is
Apoptosis.
98
Streptococcus pyogenes produces proteins called ___, which alter the surface of the pathogen and inhibit phagocytosis.
M proteins.
99
Some intracellular pathogens produce phagocyte-killing proteins called ___ that kill the phagocyte after ingestion of the pathogen.
Leukocidins.
100
The first cell type active in the innate response is usually a(n)
Phagocyte.
101
When dendritic cells ingest antigen, they migrate to the ___, where they present the antigen to T lymphocytes.
Lymph nodes.
102
The increased rate of O₂ uptake by activated phagocytes is called the
Respiratory burst.
103
Which of the following uses its cell wall glycolipids to absorb hydroxyl radicals and superoxide anions?
Mycobacterium tuberculosis.
104
Organisms such as Streptococcus pyogenes and Staphylococcus aureus that produce leukocidins and are associated with pus are called
Pyogenic pathogens.
105
A(n) ___ is a group of sequentially interacting proteins important in innate and adaptive immunity.
Complement.
106
Which of the following is NOT an example of healthcare-associated infections?
Pathogenic infections in healthy individuals.
107
Pattern recognition receptors (PRRs) detect ___ in pathogens.
Pathogen-associated molecular patterns (PAMPs).
108
Fever is a common result of endotoxin exposure due to the release of
Endogenous pyrogens.
109
Which of the following is a unique feature of adaptive immunity compared to innate immunity?
Specificity for individual pathogens.
110
Neutrophils are involved in
Early innate immune responses to infection.
111
Inflammation is triggered by
Cytokines released from immune cells.
112
Phagocytes directly kill pathogens using
Reactive oxygen species and enzymes.
113
The immunological response characterized by specificity and memory is
Adaptive immunity.
114
SYBR Green, commonly used in qPCR, binds nonspecifically to
dsDNA.
115
Bacteremia is a term used
To indicate the presence of bacteria in the blood.
116
Which of the following must be accomplished FIRST in order to conduct RT-PCR?
Complementary DNA must be synthesized from RNA.
117
The most common of all nosocomial infections are ___ infections.
Urinary tract.
118
MacConkey agar and eosin-methylene blue (EMB) agar are ___ media.
Both selective and differential.
119
An Etest® is a clinical tool used for the determination of
The minimum inhibitory concentration (MIC) value of an antimicrobial agent.
120
The component that enriches chocolate agar is
Heat-lysed blood cells.
121
Modified Thayer-Martin (MTM) agar
Incorporates antibiotics into the medium.
122
The oxygen-free gas commonly employed during anoxic incubation of a bacterial culture is a mixture of
Nitrogen and carbon dioxide.
123
Which type of medium typically contains an indicator dye?
Differential but not selective.
124
Some antibiotics inhibit protein synthesis by disruption of translation through interactions with the
Ribosome.
125
The disk-diffusion test is used for
Assessing antimicrobial activity.
126
Which of the following immunological tests would allow the specific identification of a microorganism directly in a patient specimen?
Fluorescent antibody (FA).
127
EMB agar preferentially selects for the growth of ___ bacteria.
Gram-negative.
128
Latex bead agglutination tests are
Rapid and reliable tests used for the detection of certain bacteria as well as certain serum antibodies.
129
The first antibiotic to be characterized was a
β-lactam.
130
One advantage of fluorescent antibodies is that
It may be applied directly to tissue.
131
Which of the following is a mechanism of aminoglycosides?
Targeting the 30S ribosomal subunit.
132
Which of the following would be useful for treating Candida?
An azole.
133
The blotting of proteins from polyacrylamide gels to nitrocellulose paper, and the subsequent identification by specific antibodies, is called a(n) ___ blot.
Western.
134
Widespread antimicrobial drug resistance is usually passed by
Horizontal gene transfer.
135
Most drug-resistant bacteria isolated from patients contain a(n)
R plasmid.
136
Antibody titer can be measured by
Agglutination.
137
Compared with other precipitation tests, agglutination tests are
More sensitive.
138
Blood agar is an example of a(n) ___ medium.
Differential.
139
A mechanism for penicillin resistance in bacteria is
Splitting the β-lactam ring of the antibiotic.
140
Chocolate agar is an example of a ___ medium.
Nonselective enriched.
141
Which of the following antibiotics inhibits RNA synthesis?
Rifampin.
142
The tuberculin skin test looks to identify ___ specific to Mycobacterium tuberculosis.
Delayed hypersensitive (DTH) TH1 cells.
143
Which of the following is a novel antimicrobial target?
Disruption of lipid biosynthesis.
144
The basis for blood typing is referred to as
Hemagglutination.
145
Which bacterium shows a characteristic green sheen when grown on eosin-methylene blue (EMB) agar?
Escherichia coli.
146
Protein A, commonly used in immunoblots, is derived from
Staphylococcus.
147
Two common or important bacterial pathogens found in the blood are
Pseudomonas aeruginosa and Escherichia coli.
148
A gram-negative, oxidase-positive diplococcus growing on chocolate agar likely belongs to the genus
Neisseria.
149
___, periodic reports on the susceptibility of clinically isolated organisms to antibiotics in current local use, are valuable for tracking the emergence of new antibiotic-resistant strains of pathogens.
Antibiograms.
150
___ defines the lowest quantity of an antigen that can be detected in a serological test.
Sensitivity.
151
Which of the following prevents supercoiling of bacterial DNA?
Quinolones.
152
The use of selected culture media and incubation conditions to isolate microorganisms from samples is known as a(n)
Enrichment culture.
153
How is drug-resistant Neisseria gonorrhoeae treated?
With synthetic analogs of tetracycline.
154
Which of the following microbial groups is MOST resistant to desiccation due to their cell wall?
Gram-positive.
155
The causative agent of streptococcal pharyngitis, also known as 'strep throat,' is
Streptococcus pyogenes.
156
Impetigo is due to an infection caused by
Either Staphylococcus aureus or Streptococcus pyogenes.
157
Rheumatic fever is
An autoimmune disease.
158
Encapsulated strains of Streptococcus pneumoniae are particularly pathogenic because they
Are potentially very invasive.
159
Once a person has been infected with Neisseria gonorrhoeae, the individual
Acquires no immunity and thus could be reinfected immediately.
160
Which statement is TRUE about Streptococcus pneumoniae and the lung infection it causes?
Streptococcus pneumoniae can spread from the focus of infection as a bacteremia.
161
Which of the following is used to identify methicillin-resistant Staphylococcus aureus?
Selective media, differential media, and PCR.
162
The causal agent of gastric ulcers is
Helicobacter pylori.
163
The diphtheria component of the DTaP vaccine is a(n)
Toxoid.
164
Which of the following is NOT a staphylococcal disease?
Strep throat.
165
Isonicotinic acid hydrazide (INH) is an antibiotic used in the treatment of tuberculosis. It affects the synthesis of
Mycolic acid.
166
Tuberculoid Hansen’s disease is caused by the pathogen
Mycobacterium leprae.
167
Serious acute cases of diphtheria are treated with antibiotics and
Diphtheria antitoxin.
168
The unique antigenic determinants of the 90 serotypes of Streptococcus pneumoniae are found
On the capsular polysaccharides.
169
Which of the following are group A Streptococcus (GAS)?
Streptococcus pyogenes.
170
Which of the following does NOT apply to bacterial pathogens affecting the respiratory tract?
Most respiratory bacterial pathogens do not respond to antibiotic therapy.
171
Whooping cough is frequently observed in
Children under 6 months of age.
172
Pus formation in skin lesions caused by Staphylococcus aureus infections is in part due to production of
Leukocidin.
173
A positive tuberculin test means a patient
Has been previously exposed to Mycobacterium tuberculosis.
174
The inflammatory response to Corynebacterium diphtheriae infection results in the production of a lesion called a(n)
Pseudomembrane.
175
Another name for pertussis is
Whooping cough.
176
The causative agent of Hansen’s disease is
Mycobacterium leprae.
177
Staphylococcus aureus produces ___, an enzyme that results in the accumulation of fibrin around the bacterial cells.
Coagulase.
178
Which of the following is NOT a sign of scarlet fever?
Impetigo.
179
Individuals who have an active case of tuberculosis may spread the disease simply by
Coughing near uninfected individuals.
180
Transmission of Mycobacterium leprae involves
Both direct contact and the respiratory route.
181
Meningitis can be caused by
Viral, bacterial, or fungal infections.
182
Resident staphylococci in the ___ seldom cause disease.
Upper respiratory tract.
183
Which rickettsial disease can be transmitted by contaminated milk?
Q fever.
184
Control of certain diseases is nearly impossible because we cannot
Control vector and reservoir animals or eradicate organisms from the soil.
185
Animal diseases transmissible to humans are known as
Zoonoses.
186
Which insect functions in the host-to-host transmission of typhus?
Body louse.
187
Which of the following would be the best strategy to prevent the spread of yellow fever and dengue fever into the southern United States?
Mosquito avoidance and eradication.
188
Which of the following diseases CANNOT easily be controlled by vector elimination?
Rabies.
189
Very few preventative measures are taken against anthrax because
The general population is not exposed to infected materials or animals regularly.
190
Animal-transmitted diseases are generally spread to accidental hosts by
Direct contact, aerosols, and bites.
191
Soldiers or refugees in crowded unsanitary conditions are MOST susceptible to which rickettsial disease?
Typhus.
192
The rickettsias can be cultured in
Laboratory animals.
193
The rickettsias are divided into groups based loosely on
The types of clinical disease they produce.
194
Which of the following pathogens is spread by infected lice?
Rickettsia prowazekii.
195
Which rickettsial disease can lead to endocarditis?
Q fever.
196
Which disease has been mistakenly diagnosed as measles or scarlet fever due to similarities in rash appearance?
Rickettsial diseases.
197
What virulence factor(s) of Yersinia pestis prevent(s) phagocytosis by cells of the immune system?
The capsule.
198
Rickettsial disease detection/identification includes which of the following?
Latex bead agglutination assays, ELISA, and PCR assays.
199
The disease whose symptoms are most closely related to the symptoms of chronic syphilis is
Latent Lyme disease.
200
Tetanus develops from a puncture wound because
Endospores germinate in anoxic conditions.
201
Murine toxin is a ___ that plays a role in both the murine and human forms of the disease.
Yersinia pestis endotoxin.
202
In bubonic plague, buboes are swellings formed in the lymph nodes and filled with
Yersinia pestis.
203
The primary disease reservoir for plague is
Rats.
204
A person is MOST likely to contract diseases such as Rocky Mountain spotted fever and ehrlichiosis if he or she visits/participates in
Camping and hiking in the backcountry.
205
The most severe and fatal form of anthrax is
Inhalation anthrax.
206
Which of the following was an emerging mosquito-borne disease in the early 2000s but has now decreased in frequency?
West Nile fever.
207
The causative agent of Lyme disease is ___, which is carried primarily by the ___.
Borrelia burgdorferi / Ixodes sp. (deer tick).
208
Hantavirus pulmonary syndrome is a viral respiratory disease caused by contact with
Rodents.
209
The causative agent of dengue fever is
A flavivirus.
210
Controlling most rickettsial diseases involves managing
The vector.
211
If Lyme disease is not treated early, it can infect the
Central nervous system.
212
The MOST important potential common source of infectious disease is
Water.
213
The degree of susceptibility a food has to microbial activity is determined by its
Chemical characteristics, physical characteristics, and water content.
214
Flour and sugar are classified as ___ foods.
Nonperishable.
215
At what temperature are most household freezers kept?
-20°C.
216
The rate of contaminant microbial growth during the exponential phase in food depends on
Temperature, nutrient value, and water content.
217
Psychrotolerant microorganisms can survive and grow at
Refrigeration temperatures.
218
The pH of MOST foods is
Neutral or acidic.
219
The principle behind salt or sugar preservation is to
Reduce water activity (aw).
220
Pickling is a type of food preservation utilizing
Weak acids.
221
The Staphylococcus aureus toxins are
Superantigen toxins.
222
Staphylococcus aureus is a common foodborne disease because it
Grows on many foods, is present in some humans that work in food processing, and produces several heat-stable enterotoxins.
223
Severe cases of Staphylococcus aureus food poisoning may require treatment
For dehydration.
224
Clostridium perfringens food poisoning leads to diarrhea because
The permeability of the intestinal epithelium is altered by the toxin it produces.
225
Clostridium botulinum is a gram-___ rod that produces an ___.
Positive endospore-forming / exotoxin.
226
Salmonellosis is most frequently caused by
Salmonella enterica serovars Typhimurium and Enteriditis.
227
Verotoxin can cause
Hemorrhagic diarrhea, liver failure, and brain damage.
228
ETEC strains produce one of two heat-___ diarrhea-producing ___.
Stable / enterotoxins.
229
The Campylobacter spp. are
Microaerophiles.
230
Listeria monocytogenes is
Acid-, cold-, and salt-tolerant.
231
Listeriosis is diagnosed from ___ cultures and treated with ___.
Blood or spinal fluid / intravenous antibiotics.
