Micro Flashcards
1) Your patient is a 30-year-old man who has frequent episodes of herpes labialis. He asks you to tell him something about herpes simplex virus type 1 (HSV-1). Which one of the following would be the most accurate statement to make?
A) Acyclovir can eradicate the latent state of HSV-1 but not HSV-2
B) The main site of latency by HSV-1 is the neurons in the sensory ganglia of the face. C) HSV-1 is an enveloped virus that has a DNA genome and a DNA polymerase in the virion
D) The lesions of primary HSV-1 infections are less extensive and less severe than the lesions of recurrent HSV-1 infections
E) The laboratory diagnosis of HSV-1 infections typically involves the detection of a greater than fourfold rise in antibody titer against the virus
B) The main site of latency by HSV-1 is the neurons in the sensory ganglia of the face.
2) Regarding varicella-zoster virus (VZV), which one of the following is most accurate? A) High-dose acyclovir can eliminate the latent state caused by VZV
B) The principal site of latency of VZV is in the nucleus of motor neurons
C) Domestic animals, such as pigs and chickens, are the main reservoir for VZV
D) The vaccine against varicella contains all three serotypes of formalin-killed VZV as the immunogen
E) When zoster occurs in an immunocompromised patient, acyclovir should be given to prevent disseminated infection.
E) When zoster occurs in an immunocompromised patient, acyclovir should be given to prevent disseminated infection.
3) Regarding cytomegalovirus (CMV), which one of the following is most accurate?
A) CMV is usually acquired by the fecal-oral route in adults
B) Neonates born from infected mothers should be given the subunit vaccine
C) Reactivation of CMV in sensory ganglion cells leads to painful vesicles along nerves D) Lamivudine should be used to treat CMV infections in immunocompromised patients E) CMV infection of a fetus during the first trimester results in more congenital abnormalities than infection in the third trimester.
E) CMV infection of a fetus during the first trimester results in more congenital abnormalities than infection in the third trimester.
4) Regarding Epstein-Barr virus (EBV) and infectious mononucleosis, which one of the following is most accurate?
A) EBV enters the latent state primarily in CD4-positive helper T cells
B) Approximately 10% of people have been exposed to EBV
C) People with infectious mononucleosis produce antibodies that agglutinate sheep red cells.
D) The atypical lymphs in the blood of people with infectious mononucleosis are EBV-infected T helper cells
E) Patients with deficient cell-mediated immunity should receive passive-active immunization against EBV
C) People with infectious mononucleosis produce antibodies that agglutinate sheep red cells.
5) A 26-year-old man develops myopericarditis with mild congestive heart failure that increases over several weeks. Coxsackievirus B5 infection is diagnosed. Which of the following clinical syndromes is not associated with coxsackievirus infections? A) Herpangina B) Myocarditis or pericarditis C) Aseptic meningitis D) Acute hemorrhagic conjunctivitis E) Progressive postpolio muscle atrophy.
E) Progressive postpolio muscle atrophy.
6) A 3-month-old child develops fever, restlessness, and unusual crying. These are followed by apparent lethargy. Physical examination shows a normal-appearing infant who is minimally responsive to stimuli. A lumbar puncture yields cerebrospinal fluid with 200 white blood cells per microliter, predominantly lymphocytes. Acute aseptic meningitis is diagnosed, probably caused by an enterovirus. Enteroviruses are characterized by?
A) Latency in sensory ganglia and reactivation primarily in immunocompromised patients B) Transmission primarily by the fecal-oral route.
C) The presence of a DNA polymerase enzyme
D) The entry of cells following binding to the intercellular adhesion molecule-1 (ICAM-1) receptor
E) Undergoing antigenic shift and drift
B) Transmission primarily by the fecal-oral route.
7) Which virus is not a zoonotic virus? A) Epstein-Barr virus. B) Hantavirus C) Ebolavirus D) SARS-Coronavirus E) Influenza-A (H1N1) virus
A) Epstein-Barr virus.
8) One month after school has been let out for the summer, a 16-year-old girl develops fever, myalgia, and headache. An outbreak of an illness with similar symptoms caused by an echovirus is known to be occurring in the community.
The primary anatomic site of echovirus multiplication in the human host is?
A) The muscular system
B) The central nervous system
C) The alimentary tract.
D) The blood and lymph system E) The respiratory system
C) The alimentary tract.
9) Which of the following statements about enteroviral meningitis is true? A) Vaccines are generally available to protect against the disease
B) The main symptom is muscle paralysis
C) Transmission is usually by the fecal-oral route.
D) The causative agents do not survive well in the environment E) Recovery is rarely complete
C) Transmission is usually by the fecal-oral route.
D) The causative agents do not survive well in the en
10) Which of the following properties of enteroviruses is not shared by rhinoviruses? A) Single-stranded RNA genome
B) Production by cleavage of viral proteins from a polyprotein precursor
C) Resistance to lipid solvents
D) Stability at acid pH (pH 3.0). E) Icosahedral symmetry
D) Stability at acid pH (pH 3.0).
11) Outbreaks of hand-foot-and-mouth disease, characterized by oral ulcerations and vesicular rashes, occur and may result in infant deaths. The disease is caused by? A) Foot-and-mouth disease virus.
B) Chickenpox virus
C) Nonpolio enteroviruses D) Rhinoviruses
E) Rubella virus
A) Foot-and-mouth disease virus.
12) Live, attenuated oral polio vaccine (OPV) and inactivated polio vaccine (IPV) are both available. In which one of the following situations is the use of OPV preferred?
A) Routine infant vaccination
B) Mass immunization programs in areas of high poliomyelitis endemicity.
C) Adult immunization
D) Patients who are receiving immunosuppressive therapy E) Family contacts of immunocompromised patients
B) Mass immunization programs in areas of high poliomyelitis endemicity.
13) Each of the following clinical syndromes is associated with infection by picornaviruses except?
A) Myocarditis or pericarditis
B) Hepatitis
C) Mononucleosis. D) Meningitis
C) Mononucleosis.
14) Which of the following statements is most characteristic of poliovirus? A) The genome is double-stranded DNA
B) Intestinal replication is extensive.
C) Congenital infections are frequent
D) A skin test can identify previous exposure E) Amantadine chemoprophylaxis is effective
B) Intestinal replication is extensive.
15) Coxsackieviruses appear worldwide particularly in young persons. Their epidemiology and pathogenesis most closely resembles?
A) Adenoviruses
B) Influenza A
C) Polioviruses. D) Hepatitis A E) Mumps
C) Polioviruses.
16) Which of the following is the site of latent infection of Varicella zoster virus following primary infection? A) Lymphoid tissues B) Kidney C) Neurons. D) Skin E) Salivary glands
C) Neurons.
17) A 20-year-old university student was brought to the emergency department by his dorm mate with a petechial rash, headache, nuchal rigidity, and vomiting. Which of the following describes the most likely causal agent?
A) Gram-negative coccus, capsule, ferments maltose.
B) Gram-negative coccus, ferments glucose only
C) Gram-negative coccobacillus, capsular serotype b
D) Gram-positive coccus, alpha hemolytic, optochin sensitive E) Gram-positive rods, growth at 4°C
A) Gram-negative coccus, capsule, ferments maltose.
18) Which one of the following agents lacks nucleic acid? A) Bacteria B) Viruses C) Viroids D) Prions E) Protozoa
D) Prions
19) One major advantage of the conjugate meningococcal vaccines compared with the polysaccharide vaccine is?
A) Stimulation of mucosal secretory IgA
B) Fewer side effects
C) A T cell-dependent response to vaccine is induced. D) Inclusion of serogroup B
C) A T cell-dependent response to vaccine is induced.
20) A previously healthy 12-month-old girl presents to the emergency department with a 1- day history of fever, vomiting, and lethargy. The child has had a few upper respiratory infections and ear infections, but her history is otherwise unremarkable. The family stated that they did not vaccinate their child due to religious objections. The child’s temperature is 38.8°C. On the physical examination, Brudzinski’s and Kernig’s signs are positive. An organism from the cerebrospinal fluid (CSF) does not grow on blood or MacConkey agars but does grow on media supplemented with hemin and nicotinamide adenine dinucleotide (NAD). Which of the following would most likely be observed on Gram stain from the girl’s CSF?
A) Gram-positive rod
B) Gram-negative coccobacilli. C) Gram-negative diplococci
D) Gram-positive diplococci
E) Gram-positive cocci in clusters
B) Gram-negative coccobacilli.
21) A 40-year-old woman presents with a 1-day history of fever, headache, vomiting, and abdominal cramps. She was diagnosed with lung cancer three months ago and is currently undergoing chemotherapy. A lumbar puncture is performed, and the CSF shows pleocytosis with a neutrophil predominance, gram-positive rods, elevated protein, and decreased glucose. The most likely virulence mechanism mediating this infection is:
A) A polysaccharide capsule
B) Intracellular survival and spread. C) Lipopolysaccharide (LPS)
D) Pili
E) Superantigen production
B) Intracellular survival and spread.
22) Which of the following is a characteristic of abnormal prions (PIPSc)? A) Effectively disinfected by heating to at least 100°C
B) Genome has RNA but not DNA
C) Levels remain constant throughout disease
D) Normally found in the tissues of animals and humans E) Occur due to the misfolding of normal prions protein.
E) Occur due to the misfolding of normal prions protein.
.23) Which of the following organisms is most likely the cause of this patient’s death? A) Clostridium tetani
B) Herpes simplex virus
C) Rabies virus.
D) Toxoplasma gondii E) West Nile virus
C) Rabies virus.
24) Which of the following scenarios is most probable for transmission of this organism? A) Animal bite. B) Cat litter box C) Mosquito bite D) Sexual E) Unwashed wound
A) Animal bite.
