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Old 06-27-2011
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Question Diagnosis of P.carinii

One of the most clinically significant infections in patients with AIDS is Pneumocystis carinii pneumonia (PCP). PCP is a treatable disease; therefore, rapid diagnosis is essential. The method of choice for detection of P. carinii in respiratory specimens is

a. Methenamine-silver stain
b. Toluidine blue stain
c. Direct fluorescent antibody (DFA) microscopy
d. Indirect fluorescent antibody (IFA) microscopy

e. Culture in rat lung cells


Last edited by earthpole; 06-27-2011 at 12:39 AM. Reason: modify the font
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Old 06-27-2011
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Quote:
Originally Posted by earthpole View Post
One of the most clinically significant infections in patients with AIDS is Pneumocystis carinii pneumonia (PCP). PCP is a treatable disease; therefore, rapid diagnosis is essential. The method of choice for detection of P. carinii in respiratory specimens is

a. Methenamine-silver stain
b. Toluidine blue stain
c. Direct fluorescent antibody (DFA) microscopy
d. Indirect fluorescent antibody (IFA) microscopy

e. Culture in rat lung cells

My ans

B)

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Old 06-27-2011
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Quote:
Originally Posted by earthpole View Post
One of the most clinically significant infections in patients with AIDS is Pneumocystis carinii pneumonia (PCP). PCP is a treatable disease; therefore, rapid diagnosis is essential. The method of choice for detection of P. carinii in respiratory specimens is

a. Methenamine-silver stain
b. Toluidine blue stain
c. Direct fluorescent antibody (DFA) microscopy
d. Indirect fluorescent antibody (IFA) microscopy

e. Culture in rat lung cells

A. Silver stain?
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Old 06-27-2011
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method of choice for detection?

DFA or IFA (I don't remember which one of the two techniques though)
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Old 06-27-2011
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my ans is b
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Old 06-27-2011
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Direct fluorescent antibody (DFA) is the test of choice but since the question clearly states rapid diagnosis is required i would go with
a. Methenamine-silver stain
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Default a.

a) methenamine silver stain
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answer is C
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Old 06-27-2011
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Both methenamine-silver and toluidine blue stain pneumocysts nonspecifically. These preparations are difficult to read because background material may nonspecifically stain black or blue. Pneumocystis carinii cannot be routinely cultured from human specimens. Both IFA and DFA tests are FDA-approved and available for detection of P. carinii. The advantage of DFA is that it is quicker (45 to 60 min versus 3 h) and there is less nonspecific fluorescence observed in the preparation.
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