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Achey Amoeba

An 18-year-old healthy male had noted fatigue and some generalized muscle aches for several days. He awoke on the morning of October 31 (which he distinctly remembered as he had been planning to go to a Halloween Ball as an amoeba) feeling chilly and suffering from a sore throat and a severe frontal headache. He also felt hot, and recorded a temperature of 102. Over the next several days he became increasingly bothered by a persistent non-productive cough, along with his headache and fever. He also noted increasing severity of muscle aches and pains. On November 2, he complained of a severe left earache, and the next day consulted a physician.

Question 1 - Single Best Answer

Your differential diagnosis, at this point, would include which of the following?   Bugs Database

meningitis, "strep" throat, flu, pneumococcal pneumonia, Legionnaire's disease
mycoplasma pneumonia, Rocky Mt. spotted fever, shigellosis
"walking" pneumonia, botulism, otitis media, psittacosis
mycoplasma pneumonia, "Strep" throat, flu, chlamydial pneumonia, otitis media
syphilis, gonorrhea, tetanus, dysentery, otitis media

The doctor determined that the young man lived alone and had no pets. He did not smoke and only very occasionally drank alcohol. He had a girlfriend with whom he had a monogamous relationship.

Your differential diagnosis correctly listed chlamydial pneumonia. Chlamydia can cause a lower respiratory tract infection that resembles "walking" pneumonia.

Question 2 - Single Best Answer

What species of Chlamydia would be most likely to cause pneumonia in this young man?   Bugs Database

none, Chlamydia don't cause pneumonia, just pneumonitis
Chlamydia psittici
Chlamydia pneumoniae
Chlamydia trachomatis

Question 3 - Single Best Answer

The young man's age, and the fact that he did not smoke or drink would tend to rule out which of the following?   Bugs Database

Legionnaire's disease
Strep throat
influenza
mycoplasma pneumonia
otitis media

Physical examination by the doctor revealed a temperature of 101 and a pulse rate of 105/min. Blood pressure was 124/76, and respirations were 24/min.

Question 4 - Single Best Answer

Of these values, which is/are abnormal?   Bugs Database

temperature and blood pressure
only temperature
only pulse and respiration
temperature, pulse, and respiration
all of the values

The patient looked reasonably well but was obviously in pain because of the earache and the distressing and persistent dry cough. The left tympanic membrane was slightly erythematous. A single tender enlarged cervical lymph node was palpable below the left ear lobe.

Question 5 - Single Best Answer

The fact that the patient was reasonably well would tend to rule out which disease?   Bugs Database

mycoplasma pneumonia
Legionnaire's disease
meningitis
pneumococcal pneumonia
several of the above

Question 6 - Single Best Answer

The earache is probably due to?   Bugs Database

otitis media caused by S. pneumonia (pneumococcus)
otitis media caused by H. influenzae
infection by Mycoplasma pneumonia
referred pain from his "Strep" throat
a side effect of influenza virus mediated by interferon

Question 7 - Single Best Answer

What other tests would you do at this point?   Bugs Database

throat culture
blood count
chest X-ray
auscultation of the chest
all of the above

Hematocrit was normal. Leucocyte count was 8000 cells per cubic millimeter, with a normal differential. No beta hemolytic colonies from the throat culture grew on blood agar.

Question 8 - Single Best Answer

The leucocyte count

indicates an oncogenic process
indicates an infectious disease
is normal

Question 9 - Single Best Answer

The lack of beta hemolytic colonies from the throat culture indicates?   Bugs Database

he does not have influenza, as the flu virus produces beta hemolytic colonies on blood agar
he does not have otitis media caused by H. influenzae
he does not have a sore throat caused by Streptococcus pyogenes
he does not have mycoplasma pneumonia
he does not have Legionellosis

Examination of the chest revealed crackling inspiratory rales over the right lower lung field posteriorly.

Question 10 - Single Best Answer

The rales and their position indicate?   Bugs Database

a normal state
bronchoconstriction
fluid in the trachea and bronchi
fluid in the lungs

X-ray showed a stringy, poorly delineated infiltrate in the most posterior and inferior segment of the right lower lobe.

A satisfactory sputum sample could not be obtained.

Question 11 - Single Best Answer

How does this X-ray differ from what would be seen with pneumococcal pneumonia?

The position of the infiltrate would be different
There would likely be more consolidation with pneumococcal pneumonia.
The infiltrate would be only interstitial in pneumococcal pneumonia
It is always bilateral in pneumococcal pneumonia

Question 12 - Single Best Answer

Most of the signs and symptoms indicate a diagnosis of mycoplasma pneumonia. The lack of a good sputum sample is one of the signs pointing to this diagnosis. Sometimes patients with this disease do produce some sputum, however. When they do, the following is seen on a Gram stain:   Bugs Database

a few neutrophils and no bacteria
Gram positive cocci in bunches
Gram negative diplococci inside white cells
Gram positive lancet-shaped diplococci

Question 13 - Single Best Answer

How could you verify a diagnosis of Mycoplasma pneumonia?   Bugs Database

aspirate the lung and grow the organism on blood agar - - it should be alpha hemolytic.
aspirate the lung and do dark field microscopy
look for cold hemaglutinnins in the patient's serum
look for a rise in complement-fixing antibodies to mycoplasma in the patients serum
both C and D are correct

Question 14 - Single Best Answer

What is the major virulence mechanism of Mycoplasma pneumonia?   Bugs Database

intracellular growth
a polysaccharide capsule to prevent phagocytosis
an enzyme that hydrolyzes IgA
an adhesin on the tip of the organism called P1
a pilus adhesin

Question 15 - Single Best Answer

Would you prescribe penicillin for this disease?   Bugs Database

yes
no

Question 16 - Single Best Answer

Penicillin would not work in this disease because?   Bugs Database

the organism produces a beta lactamase
the organism produces a beta hemolysin
the organism makes fried egg colonies
the organism has no cell wall
the organism has sterols in its cell membrane

Question 17 - Single Best Answer

Where did the young man acquire the mycoplasma?   Bugs Database

via sexual contact
from his normal flora
at the blood bank when he gave blood
from someone else with the disease via the respiratory route
from unpasteurized milk

Question 18 - Single Best Answer

In your book look up some of the other mycoplasma. One found in the G-U tract is?   Bugs Database

M. avium intracellularae
M. hominis
M. salivarium
Ureaplasm urealyticum
two of the above

   

 Location: http://medinfo.ufl.edu/year2/mmid/a14aq.html
  Updated: October 6, 2005

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