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Worksheetsmicro test 4
Total questions: 123
Worksheet time: 1hrs 2mins
Genomic islands have all of the following features EXCEPT
they are flanked by phage or plasmid genes.
the ratio of GC/AT nucleases.
they do not need toxins or secretion systems.
they encode clusters of genes that contribute to the fitness of the organism.
Which statement about horizontal gene transfer is correct?
Few pathogenicity islands are generated by horizontal transmission.
Horizontal gene transfers move whole blocks of DNA from one organism to another.
Horizontal gene transfer helps pathogens evolve.
All genes code for toxins.
All of the following are methods of microbial attachment EXCEPT
capsids
pili
fimbriae
type IV secretion systems
The fimbriae of E. coli is an example of a(n)
adhesion
receptor
endotoxin
exotoxin
Type I pili are different from type IV pili in that type I pili
are static structures.
are thin and flexible.
allow for twitching motility.
are dynamic.
Interfering with microbial attachment results in
making a pathogenic organism nonvirulent.
disrupting toxin production.
increased formation of microbial biofilms.
increased virulence.
Biofilm infections are important clinically because
WBC easily penetrate biofilms.
bacteria in biofilms are more susceptible to antimicrobial compounds.
bacteria in biofilms can persist against host defenses.
bacteria in biofilms do not grown on medical devices.
All of the following are exotoxins EXCEPT
superantigens.
AB toxins.
plasma membrane disruption toxins.
lipopolysaccharide.
All of the following are targets for bacterial toxins EXCEPT
signal transduction.
host membranes.
DNA synthesis.
protein synthesis
Which of the following statements is FALSE?
Hemolysins lyse red blood cells.
Leukocidins destroy neutrophils.
AB toxins interfere with protein synthesis.
Protease exotoxins build proteins.
Alpha toxin secreted by Staphylococcus aureus is a
hyaluronidase.
leucocidin.
kinase.
hemolysin.
All of the following are true about cholera toxin EXCEPT that it
is an endotoxin.
is an AB toxin.
reverses the absorption process in the intestines.
causes severe diarrhea.
Endotoxins are
associated with Gram-positive bacteria.
molecules that bind nerve cells.
part of the Gram-negative cell wall.
excreted from the cell.
Which of the following is NOT an example of a bacterial secretion system that is paralogous to another molecular machine?
type 1 protein secretion system
type II protein secretion system
type III protein secretion system
type IV protein secretion system
Which of the following is true regarding type II secretion systems?
The type II secretion genes are homologous to the type IV pilus.
Type II secretion mechanisms are static with no twitching motility.
Proteins secreted by type II secretion systems are secreted directly out of the cell.
Shiga toxin is a well-known example of a protein that a type II secretion mechanism
expels.
All of the following statements about type III secretion systems are true EXCEPT
proteins are injected directly into the eukaryotic cells.
type III secretion systems are evolutionarily related to flagellar genes.
cell-to-cell contact triggers type III secretion systems.
virulence proteins secreted by type III systems alter protein synthesis.
Refer to the figure below. The secretion system displayed mirrors that of a pilus. Which secretion system is this?
type I
type II
type III
type IV
Rickettsia will not grow outside a living eukaryotic cell. What type of organism is this?
extracellular pathogen
facultative intracellular pathogen
intracellular pathogen
obligate extracellular pathogen
All of the following are ways bacteria evade phagocytic digestion and survive intracellularly EXCEPT
escaping the phagosome.
toxin production within the phagosome.
inhibiting lysosome-phagosome fusion.
survival within the phagolysosome.
Shiga toxin polypeptide B binds to surface gangliosides on target cells. If the gangliosides were
removed
polypeptide A would bind to target cells.
polypeptide A would enter the cells.
polypeptide B would not be able to bind.
Vibrio would not produce cholera toxin.
Organisms such as Shigella and Listeria are able to move from cell to cell without being detected by
the host immune system. What method are they using?
production of an actin tail that propels them from cell to cell
production of a capsule to avoid antibody binding
production of protein A molecules to bind the Fc region of antibodies
production of proteins to trigger apoptosis in host cells
All of the following are ways pathogens avoid destruction by the host immune system EXCEPT
capsules
triggering apoptosis
antigenic variations
toxin production
In viruses such as influenza, the ability to undergo a major genetic alteration is called
antigenic drift
antigenic shift
antigenic variation
antigenic binding
Antigenic drift occurs when
two viruses infect the same cell.
a new viral strain is produced.
random mutations occur in the neuraminidase spike.
random mutations occur in the hemagglutinin spike.
The human immunodeficiency virus (HIV) primarily targets which subset of immune cells?
CD8+ T cells
CD4+ T cells
macrophages
dendritic cells
All of the following statements are true about HIV EXCEPT
HIV produces a Nef protein, which prevents T-cell apoptosis.
Tat increases MHC 1 synthesis on host cells.
Nef protein inhibits a regulatory cascade that leads to apoptosis.
Tat stimulates apoptosis in infected host cells.
Cervical warts are caused by
HBV
HPV
HIV
herpes
Which of the following is true regarding the herpes virus?
It is the etiological agent of cervical warts.
The virus cannot enter into a latent state in neural ganglia.
Latent herpes virus DNA produces microRNAs that interfere with apoptosis.
Herpes viruses are double-stranded RNA viruses.
Damage from protozoan infections is due mainly to the
toxins that are released.
ability of the organism to persist within host tissue.
ability of the organism to turn on the host immune system.
cell wall components of the pathogen.
The structure labeled as “A” in the figure below is called a(n)
protease.
MIC protein.
nucleus.
actin-myosin motor.
What is the purpose of the actin-myosin motor shown in the figure below?
The pathogen uses this structure to enter the host cell.
The pathogen uses this structure to produce toxins.
The pathogen uses this structure as a secretion apparatus.
The pathogen uses this structure to prevent phagocytosis.
Protozoans use all the following mechanisms to avoid the host immune system EXCEPT
antigenic variation.
toxin production.
antigenic masking.
intracellular
Which of the following protozoans uses antigenic variation to circumvent the host immune system?
plasmodium
entamoeba
leishmania
trypanosome
All of the following are required for disease to occur. What is the second step in microbial
pathogenesis?
pathogen exit
host damage
pathogen entry
tissue attachment
Which of the following is an example of an obligate intracellular pathogen?
Listeria monocytogenes
Shigella dysenteriae
Coxiella burnetii
Streptococcus pneumoniae
Once a bacterium attaches and enters a host cell within a phagosome, the pathogen has one of three fates, depending on the pathogen. According to the figure below, Shigella and Listeria utilize which mechanism to avoid being destroyed by the host cell?
survive inside the phagosome
escape from the phagosome
prevent phagosome-lysosome fusion
induce apoptosis
According to the figure below, which of the following is true about Coxiella?
Coxiella prevents the lysosome from fusing with the phagosome.
Coxiella prevents phagosome-lysosome fusion.
Once inside the phagosome, Coxiella interferes with cell-signaling pathways.
It escapes the phagosome before lysosomal fusion.
All of the following are true about bacterial capsules EXCEPT
they are produced by intracellular pathogens to avoid the host immune system.
they coat bacterial cell wall components inhibiting phagocytosis.
the slippery nature of capsules make “grabbing” the bacterial cell difficult.
the immune system attacks encapsulated organisms with opsonizing antibodies.
The purpose of the Tat protein in an HIV infection is to
down regulate CD4 and MHC class 1 expression.
inhibit virus assembly.
accelerate HIV transcription by the host cell.
protect the cell from being killed by CD8 cytotoxic cells.
Several of the protein exotoxins produced by Bordetella pertussis act by disrupting signal transduction.
Which of the following exotoxin-target pairs is NOT properly matched?
Cholera toxin—disrupts signal transduction (increase cAMP synthesis much like in
pertussis)
Anthrax toxin—forms pores in membranes, allowing bacteria to escape vacuoles
Shiga toxin—inhibits protein synthesis, leading to hemolytic uremic syndrome
Staphylococcal alpha toxin—forms pores in membranes, leading to lysis of blood cells
Which of the following displays a pus-filled raised lesion?
1
2
3
4
Chickenpox is caused by a very contagious herpes virus that infects epidermal cells. Which of the following is characteristic of a chickenpox infection?
1
2
3
4
Which of the following lists the layers of the skin in the correct order from deepest to superficial?
stratum basale, stratum spinosum, stratum granulosum, stratum corneum
stratum corneum, stratum granulosum, stratum spinosum, stratum basale
stratum granulosum, stratum corneum, stratum basale, stratum spinosum
stratum spinosum, stratum basale, stratum corneum, stratum granulosum
All of the following are protective features of the skin EXCEPT
Langerhans cells in the epidermis.
that it is the largest organ and forms a chemical barrier.
keratinocytes secreting keratin.
melanocytes producing melanin.
Which of the following are INCORRECTLY matched?
varicella zosters—chicken pox
HHV6—roseola
poxvirus—fever blisters
parvovirus—fifth disease
An eight-year-old girl has scabs and pus-filled vesicles on her face and throat. Three weeks earlier she had visited her grandmother, who had shingles. What infection does the eight-year-old have?
chickenpox
measles
rubella
fever blisters
Koplik spots are a diagnostic indicator of
chickenpox
smallpox
measles
rubella
All of the following are transmitted via the respiratory route EXCEPT
smallpox
chickenpox
measles
warts
Measles is similar to German measles (rubella) in the fact that
they have a similar type of rash.
they are caused by the same virus.
encephalitis is a possible complication.
they can be controlled by vaccination.
Which of the follow is NOT caused by HSV-1?
cold sores
canker sores
herpes whitlow
herpes encephalitis
Which of the following is used to treat shingles?
penicillin
sulfonamide
acyclovir
fungicide
Staphylococcus aureus is responsible for all of the following EXCEPT
boils
carbuncles
acne
pimples
The etiological agent of acne is
Staphylococcus aureus
Streptococcus pyogenes
Bacillus anthrasis
Propionibacterium acnes
All of the following are virulence factors associated with S. pyogenes EXCEPT
lipopolysaccharide
capsule
M protein
lipoteichoic acid
Topical retinoids and antibiotics are commonly used to treat
cellulitis
acne
erysipelas
impetigo
Which of the following is NOT true about gas gangrene?
The organism produces considerable amounts of gas
The causative agent is Clostridium perfringens
The organism only grows on live tissue
The organism is found in the environment and in the intestines
All of the following cause conjunctivitis EXCEPT
Chlamydia trachomatis
Streptococcus pyogenes
Neisseria gonorrhoeae
Haemophilus influenza
Which of the following is used to treat opthalmia neonatorum?
penicillin
acyclovir
sulfonamide
erythromycin
Inflammation of the thin clear membrane lining the eyelid and eye is properly termed
keratitis
trachoma
conjunctivitis
opthalmia neonatorum
All of the following are used to treat chickenpox EXCEPT
aspirin
calamine lotion
antihistamines
oatmeal baths
All of the following are characteristic of Pseudomonas aeruginosa EXCEPT
Gram-positive cell wall.
resistance to many types of antibiotics.
production of pyocyanin.
exotoxin production.
The greatest single cause of infectious blindness is
neonatal gonorrheal ophthalmia.
keratoconjunctivitis.
trachoma.
pinkeye.
A patient is brought to the hospital suffering with a MRSA infection. Which of the following is the best treatment option?
acyclovir
penicillin
methicillin
vancomycin
The figure below shows the fungi Fusarium. When accidentally introduced into the eye, what type of infection does this organism cause?
fungal keratitis
parasitic keratitis
allergic conjunctivitis
trachoma
All of the following are methods used to treat C. perfringens infection EXCEPT
amputation
a hyperbaric chamber
antibiotic therapy alone
debridement
Applying your knowledge to the figure below, if a herpes zoster infection is left untreated in an immunocompromised patient, which part of the eye can be damaged?
cornea
retina
optic nerve
optic nerve
Sterile maggot therapy is often used to treat which condition?
diabetic wounds
acne
conjunctivitis
keratitis
Fungal skin diseases are diagnosed based on
PCR
KOH preparation of skin scrapes
Gram-positive stain
Gram-negative stain
All of the following are classified as dermatophytic fungi EXCEPT
Malassezia
Epidermophyton
Trichophyton
Microsporum
Which of the following statements about fungi is true?
Fungi include yeasts and bacteria.
Fungi are eukaryotic microbes.
Dermatophytes do not grow on skin.
Fungi can be named after the location of the infection.
Keratitis is inflammation of the
lens
retina
cornea
sclera
A 17-year-old boy has pus-filled cysts on his face and upper back. Microscopic examination reveals Gram-positive rods. This infection is caused by
herpes simplex virus
Propionibacterium acnes
Staphylococcus aureus
Streptococcus pyogenes
Which of the following is INCORRECTLY matched?
Haemophilus influenzae—pinkeye
Pseudomonas—conjunctivitis
Chlamydia gonorrhoeae—trachoma
Neisseria gonorrhoeae—respiratory infection
A 35-year-old woman has a red, raised rash on the inside of her thighs. Gram-stained scrapings show large budding cells with pseudohyphae. The infection is caused by
Candida albicans
herpes simplex virus
varicella—zoster virus
Staphylococcus aureus
A 45-year-old man has pus-filled vesicles distributed over his back in the upper right quadrant, his right shoulder, and the upper right quadrant of his chest. His symptoms are most likely due to
Candida albicans
herpes simplex virus
varicella—zoster virus
Staphylococcus aureus
A 40-year-old woman has vesicles and scabs over her forehead. Microscopic examination of skin scrapings shows Gram-positive cocci in clusters. The etiology is
Staphylococcus aureus
Streptococcus pyogenes
Candida
herpes
Which of the following is used to treat candidiasis of the skin or mucous membranes?
penicillin
sulfonamide
acyclovir
imidazole
Which of the following statements about congenital rubella syndrome is FALSE?
It can be prevented by vaccinating women prior to pregnancy.
It may result in deafness, blindness, and mental retardation.
It may be fatal to the unborn child.
It does not occur with subclinical infection.
Why is vaccination for rubella recommended?
It has a high mortality rate in school-age children.
Death from secondary infections is common.
There is a high incidence of congenital infections.
It is no longer recommended; rubella has been eradicated.
Which of the following is the cause of a fungal infection on the scalp?
tinea capitis
tinea corporis
tinea pedis
tenia cruris
Which organism would be the most likely to be identified in a laboratory culture of Cassi’s wound?
Staphylococcus epidermidis
Streptococcus pyogenes
Clostridium perfringens
Salmonella enterica
The structure indicated on this figure is
a bronchiole
the trachea
a main bronchus
an alveolar duct
Which of the following infections would affect the upper respiratory tract but NOT the lower respiratory tract?
the common cold
pneumonia
tuberculosis
bronchitis
Which of the following infections would affect the lower respiratory tract but NOT the upper respiratory tract?
acute otitis media
sinusitis
streptococcal pharyngitis
atypical pneumonia
Which of the following structures is considered part of the upper respiratory tract?
trachea
primary bronchi
c. alveoli
larynx
The structure indicated on this figure is a(n)
sinus
lacrimal duct
inner ear
Eustachian tube
What is the significance of the anatomical difference shown?
Adults are more prone to developing sinus infections.
Children are more prone to developing sinus infections.
Adults are more prone to developing middle ear infections.
Children are more prone to developing middle ear infections.
The Eustachian tubes connect the upper respiratory tract to the
sinuses
middle ears
inner ears
eyes
The eyes are connected to the upper respiratory tract by the
pharynx
Eustachian tube
lacrimal ducts
sinuses
A common home remedy used to treat a common cold is eating chicken soup or chicken broth. Why
might this home remedy be useful?
Broth helps to prevent dehydration and thins mucus secretions.
The salt in broth draws water out of bacterial cells by osmosis.
Chicken meat contains antiviral properties.
Broth removes the top epithelial cell layers that contain viral particles.
A secondary bacterial infection is most likely in a patient who
smokes cigarettes.
breathes humidified air.
breathes dry air.
has thin mucus secretions.
Nicotine in cigarette smoke paralyzes the cilia found on epithelium within the respiratory tract. What is
the normal function of these cilia?
They produce mucus that traps microorganisms.
They help to warm incoming air.
They aid in moving mucus to the nasal and oral cavities.
They contain macrophages that target microorganisms.
A viral disease of the lower respiratory tract would likely present with
runny nose
sinus congestion.
facial pain.
cough.
Of the viral respiratory diseases below, which is LEAST likely to present with a fever?
the common cold
croup
influenza
respiratory syncytial disease
As a result of an antigenic shift
influenza is able to evade the host immune system by presenting a new hemagglutinin
structure.
the host immune system is better able to detect and respond to influenza viruses.
the influenza viral protein M2 becomes hidden within the virion envelope.
alpha 2,6 receptors are able to bind to the alpha 2,3 sialic acid residues.
Antigenic shift is best described as a
mixing of RNA segments to form a new form of the hemagglutinin gene in influenza.
shift of influenza antigen from one geographic location to another.
mutation that changes influenza RNA polymerase.
shift that occurs when an avian strain of influenza infects a pig.
The most likely mutation to cause an influenza pandemic would be a mutation in
the head of hemagglutinin.
the stalk of hemagglutinin.
M2 protein inside the virion envelope.
influenza nucleoprotein.
Coming into contact with respiratory secretions from an infected individual is LEAST likely to spread
the common cold.
respiratory syncytial disease.
influenza.
sinusitis
A virus that primarily causes disease in the very young and may lead to complications such as low blood pressure and seizures is
type A influenza.
rhinovirus.
SARS virus.
respiratory syncytial virus.
Croup is most frequently seen in
the elderly.
middle-aged adults.
adolescents.
young children.
Compared to individuals who receive vaccinations, individuals who do not receive any vaccinations
are at higher risk of developing
sinusitis.
severe acute respiratory syndrome.
influenza.
croup.
Respiratory syncytial virus and influenza are responsible for the majority of cases of
bacterial pneumonia.
viral pneumonia.
sinusitis.
kidney failure.
A 23-year-old man arrives in the emergency room. He is currently in respiratory distress and is experiencing kidney failure and blood clots in one lung. His partner reports that he had a high fever, chills, and a cough for several days prior. The attending physician quickly orders a serum antibody test validated by the CDC when he suspects the individual may be infected with
type B influenza.
respiratory syncytial virus.
severe acute respiratory syndrome.
croup.
A day-care worker reports that two young children have been coughing all day. She first noticed that both children had runny noses a few days ago, but is not sure if they had fevers. She states that they both sound like barking seals. Most likely these children have
the common cold.
croup.
influenza.
respiratory syncytial disease.
Due to the location of infection, bacterial sinusitis may lead to complications, including
meningitis
pneumonia
bronchitis
epiglottitis
The most common cause of bacterial pharyngitis is
Streptococcus pyogenes.
Streptococcus pneumoniae.
Haemophilus influenzae.
Corynebacterium diphtheriae.
Acute otitis media is infection within the
sinuses
outer ear
middle ear
inner ear
Which of the following organisms is an intracellular pathogen capable of preventing fusion of a phagosome with a lysosome after phagocytosis has occurred?
Pseudomonas aeruginosa
Haemophilus influenzae
Mycobacterium tuberculosis
Legionella pneumophila
Some strains of the bacteria Haemophilus influenzae produce beta-lactamase enzyme that
confers antibiotic resistance to the bacteria.
allows attachment of the bacteria to cilia on host cells.
prevents immunity from forming in the host.
prevents lysosomes from fusing to phagosomes.
The differential diagnosis for a patient presenting with a fever and productive cough with bloody
sputum would likely include
tuberculosis and legionellosis.
walking pneumonia and Pseudomonas pneumonia.
inhalation anthrax and diphtheria.
whooping cough and tuberculosis.
A young boy with a sore throat, cervical lymphadenopathy, and a low-grade fever is seen by his physician. Upon examination, his physician notes a thick, grayish membrane that bleeds when scraped covering the boy’s tonsils and soft palate. A bacterial culture will most likely reveal the presence of
Corynebacterium diphtheriae.
Streptococcus pneumoniae.
Moraxella catarrhalis.
Bordetella pertussis.
The graph shown indicates the incidence of whooping cough in the United States. What information can you determine from this graph?
Approximately 40,000 individuals were infected with whooping cough in 2007.
The incidence of whooping cough in infants under one year of age in 2013 was higher
than the incidence in 2012.
Vaccination against whooping cough has become less effective in infants under the age of one year over time.
The incidence of whooping cough declined dramatically between 2005 and 2007.
The graph shown indicates the incidence of whooping cough in the United States. What information can you determine from this graph?
There was a decline in vaccination rates of infants under one year of age during the early 1990s.
The incidence of whooping cough in infants under one year of age was declining prior to 1990.
Waning immunity in adult populations has led to an increase in whooping cough.
The incidence of whooping cough in infants under one year of age was higher in 2010
than it was in 1995.
This figure shows the relative incidence of pneumonia caused by various microorganisms. Vaccines are available to prevent
all of the bacterial forms of pneumonia.
the most common and least common bacterial causes of pneumonia.
viral forms of pneumonia.
the form of pneumonia that occurs most frequently in the elderly.
A young man who enjoys spelunking, the recreational sport of exploring caves, develops a flu-like pulmonary illness along with erythema nodosum and arthralgia. The most likely fungal infection in this man is
histoplasmosis
coccidioidomycosis
cryptococcosis
blastomycosis
An AIDS patient with a fungal infection develops meningoencephalitis, which is the most prevalent form of
histoplasmosis
coccidioidomycosis
cryptococcosis
blastomycosis
The Ghon complex shown in this figure is indicative of infection by
Mycobacterium tuberculosis.
Bacillus anthracis.
Blastomyces dermatitidis.
Coccidioides immitis.
A patient with a respiratory infection who is unresponsive to treatment with antibiotics, lacks a clearly defined presentation, and has seemingly unrelated symptoms
is more likely to be infected by a fungus than a virus or bacteria.
is more likely to be infected by a virus than a fungus or bacteria.
is most likely carrying an antibiotic-resistant form of bacteria.
would likely have a positive TB skin test.
The most prevalent form of cryptococcosis is found in
young children.
AIDS patients.
the elderly.
adolescent.
Close contact with respiratory droplets from which of the following individuals is LEAST likely to cause disease?
an individual with histoplasmosis
an individual with influenza
an individual with pertussis
an individual with tuberculosis
Close contact with respiratory droplets from which of the following individuals is most likely to cause disease?
an individual with histoplasmosis
an individual with blastomycosis
an individual with cryptococcosis
an individual with tuberculosis
The diffuse infiltrate shown in this figure is indicative of
pertussis
blastomycosis
tuberculosis
pneumococcal pneumonia
Based on the symptoms described and what you know about this pathogen, which best describes Jacob’s infection?
viral lower respiratory illness
viral upper respiratory illness
bacterial lower respiratory illness
bacterial upper respiratory illness
