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Old 07-31-2010
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Bacteria Fever, nuchal rigidity & photophobia

A 14-year-old-boy is brought to the emergency department by his parents because of a high fever, headache, and stiff neck for the past 36 hours. His temperature is 38.0C (100.4F). Physical examination shows moderate nuchal rigidity and marked photophobia. Examination of cerebrospinal fluid (CSF) shows WBC 3,500 with 95% neutrophils, elevated protein, decreased glucose, and gram-positive cocci in pairs and short chains. By which of the following mechanisms does the most likely causal organism mediate its attachment to the respiratory mucosa?

A. Production of a C carbohydrate
B. Production of a hemolytic exotoxin
C. Production of a hyaluronic acid capsule
D. Production of an IgA protease
E. Production of an M protein
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Old 07-31-2010
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D. Production of an IgA protease ...sterptococcus pneumoniae..
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Old 07-31-2010
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Yup - IgA protease - S. Pneumo
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Old 07-31-2010
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Help clue already gven in the question

note that other options production of exotoxin and hyaluronic acid capsule,production of m protein are all virulence factors...and production of c carbohydrate is used in lancefield grouping of streptococci...so even if u do not know the exact answer the only good choice left is D!!
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Old 07-31-2010
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Correct Answer

Quote:
Originally Posted by faith View Post
note that other options production of exotoxin and hyaluronic acid capsule,production of m protein are all virulence factors...and production of c carbohydrate is used in lancefield grouping of streptococci...so even if u do not know the exact answer the only good choice left is D!!
Yes rightly said... Another way to approach this question, remember
SHiN
Streptococcus pneumoniae
Haemophilus influenzae
Neisseria meningitidis

All of these have capsules, all produce IgA protease & all cause Meningitis.
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The above post was thanked by:
deyneko (08-04-2010), Evergreen (10-23-2011), Pixie (08-02-2010)



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