Deck 31: Intracellular Microorganisms

Question 1

The leading cause of nongonococcal urethritis is

A) Rickettsia rickettsii.
B) Chlamydia trachomatis.
C) Chlamydia psittaci.
D) herpes simplex virus.

Answer 1

Chlamydia trachomatis.

Question 2

The causative agent of human granulocytic ehrlichiosis is

A) Anaplasma phagocytophilum.
B) Ehrlichia chaffeensis.
C) Ehrlichia equi.
D) Neorickettsia sennetsu.

Answer 2

Anaplasma phagocytophilum.

Question 3

Interferon functions as part of the innate immune system by

A) preventing viruses from infecting cells.
B) acting as an opsonin.
C) activating cells that recognize and kill virus-infected cells.
D) enhancing phagocytosis.

Answer 3

activating cells that recognize and kill virus-infected cells.

Question 4

What is most effective antibody against viruses?

A) IgA
B) IgM
C) IgG
D) IgE

Question 5

A virus differs from bacteria by

A) containing only RNA or DNA but not both..
B) being 20 to 300 millimicrons in size.
C) being one of the smallest infectious agent known to man.
D) all of the above. e. b and c.

Question 6

An individual who likes to hike in the woods each spring is prone to infection with

A) Rickettsia rickettsii.
B) Bartonella henselae.
C) Coxiella burnetii.
D) all of the above.

Question 7

Which of the following viruses is known for infecting white blood cells?

A) Herpes simplex virus
B) Epstein Barr viruses
C) Human papilloma virus
D) Both a and b

Question 8

Which of the following viral structures is used to diagnose infection with hepatitis B?

A) Surface antigen
B) DNA
C) Both a and b
D) Neither a nor b

Question 9

What viral structure makes some viruses very susceptible to freezing?

A) Capsid
B) Virion
C) Nucleocapsid
D) Envelope

Question 10

The influenza A and B viruses are examples of a/an

A) enveloped DNA virus.
B) enveloped RNA virus.
C) naked DNA virus.
D) naked RNA virus.

Question 11

Chlamydia spp. and viruses enter the host cell via

A) endocytosis.
B) budding.
C) exocytosis.
D) apoptosis.

Question 12

The retroviruses are unique in their ability to

A) infect epithelial cells.
B) transcribe their RNA into DNA and then again into RNA.
C) cause cytopathic effect.
D) be a double-stranded RNA virus.

Question 13

Urine is received for the isolation of cytomegalovirus. The virus's characteristic cytopathic effect is observed as the presence of cells

A) in grape-like clusters.
B) that are large and multinucleated.
C) with a morulae.
D) resembling owl eyes.

Question 14

A patient presents to his physician with respiratory distress, chills, malaise, and headache. A thorough history revealed that the patient is a turkey farmer. He remarked that he had received a shipment of turkeys last week to sell for the upcoming holidays. A complement fixation test identified the source of his infection. The causative agent is probably

A) respiratory syncytial virus.
B) Chlamydophilia pneumoniae.
C) Chlamydophila psittaci.
D) Coxiella burnetii.

Question 15

Which procedure allows for the identification of influenza and parainfluenza viruses when there is no characteristic cytopathic effect detected on the inoculated cell line?

A) Enzyme immunoassay
B) Hemadsorption
C) Polymerase chain reaction
D) Shell vial assay

Question 16

A 1-year-old male was brought to the clinic in September because he developed fever, chest congestion, rhinorrhea, and a "barking" cough three days previously. There was no sputum production, nausea, or vomiting. His medical history was significant only for recurrent otitis media. On examination he had a temperature. He was in no acute distress and had audible obstructive upper airway sounds. His throat was red. The initial impression was that he had croup. Specimens were sent for viral culture. His symptoms were relieved with the use of a humidifier at home. Ten days later a virus was identified from a nasopharyngeal specimen only after hemadsorption studies were done on the virus culture.
What is the most likely virus infecting this child?

A) Respiratory syncytial virus
B) Parainfluenzae virus
C) Influenza virus
D) Rhinovirus

Question 17

Iodine-stained inclusions in McCoy cell monolayers are used to identify the obligate intracellular bacterial pathogen that causes

A) trachoma.
B) pneumonia.
C) Rocky Mountain spotted fever.
D) Q fever.

Question 18

A 25-year-old male had been hiking in Southeast Missouri. He presented to his physician with headache, fever, and myalgia. He noted in his history many tick bites on his legs. The physician suspected Rocky Mountain spotted fever, but the serology proved to be negative and the patient did not have a rash.
Routine culture of blood and bone marrow were negative. An observant medical laboratory scientist in the hematology department noted an unusual inclusion on the stain of the patient's bone marrow smear as seen in the image provided.
Source: Filipe Dantas-Torres
Based on this additional finding, the physician should now suspect

A) Anaplasma phagocytophilum.
B) Ehrlichia chaffeensis.
C) Rickettsia rickettsii.
D) Chlamydia trachomatis.

Question 19

Infection of the endothelial cells of the blood vessels is characteristic for

A) Neorickettsia sennetsu.
B) Coxiella burnetii.
C) Rickettsia rickettsii.
D) Ehrlichia ewingii.

Question 20

Differentiation of the type of influenza virus, such as type A versus B, is important because

A) it determines if additional testing is necessary.
B) antiviral agents used for treatment depend on the type identified.
C) antigenic shift can cause the emergence of a new strain.
D) the information is used to create the vaccine for the next year.