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  #1  
Old 04-12-2011
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Bacteria Contact Lens Infection - Microbiology Question!

A 30-year-old female using home-made saline solution for the disinfection and tap water for storing her contact lenses . She noticed redness of her eyes and deterioration of vision and visited an ophthalmologist who diagnosed her with severe retinitis.
Culture of the water as well as vitreous fluid would most likely reveal

a. Naegleria
b. Pneumocystis
c. Acanthamoeba
d. chlamydia
e. staphylococcus
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Good question, presuming this lady is in the US, I would take out the parasites A) C) (not water spread here at least) and D) too because of no sexual contact?

B) doesn't make sense either, cause it causes pneumonia in AIDS patients.

We are left with E) staph, which could be the answer. But really not sure.

So i'm left with no possible answer choices.

I'll guess E).

Dumb lady, why couldn't she just use contact lens solution
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Quote:
Originally Posted by patelMD View Post
Good question, presuming this lady is in the US, I would take out the parasites A) C) (not water spread here at least) and D) too because of no sexual contact?

B) doesn't make sense either, cause it causes pneumonia in AIDS patients.

We are left with E) staph, which could be the answer. But really not sure.

So i'm left with no possible answer choices.

I'll guess E).

Dumb lady, why couldn't she just use contact lens solution
no no Take a second look, think deeper lol
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Quote:
Originally Posted by tinhi View Post
no no have a second look, think deeper lol
Hm... Acanthamoebia?
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Old 04-12-2011
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Infection from contact lens solution => Acanthamoeba (aCONThamoeba)
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contact lens is a buzzword for acanthamoeba....
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Contact lens-- acanthamoeba
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There was a big recall of contact lens solution a few years ago for acanthamoeba...

@PatelMD: a few people do die every year in the U.S. from Naegleria infection (not from contacts, but from swimming in muddy-bottomed freshwater ponds)...
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Quote:
Originally Posted by Mondoshawan View Post
There was a big recall of contact lens solution a few years ago for acanthamoeba...

@PatelMD: a few people do die every year in the U.S. from Naegleria infection (not from contacts, but from swimming in muddy-bottomed freshwater ponds)...
Thanks, I didn't know about the naeglaria and swimming in ponds, I meant drinking water contamination

And wasn't the recall for Renu due to fungal infections?
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C. Acanthamoeba

MCC of contact lens associated infetion
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Quote:
Originally Posted by patelMD View Post
Thanks, I didn't know about the naeglaria and swimming in ponds, I meant drinking water contamination

And wasn't the recall for Renu due to fungal infections?
Oh yeah, that was the same year I think! Not a good year for contact lens wearers... This is the one I was thinking of: http://uk.reuters.com/article/2007/0...22758320070527
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Yeah, it's c. acanthamoeba.

Acanthamoeba infect the cornea (in immunocompetent persons) when contact lenses are not properly cleaned. This corneal infection (keratitis) can lead to blindness.

Also, remember that Naegleria fowleri will cause a sudden deadly meningoencephalitis in immunocompetent persons (think of the kids on spring break who went diving in a warm water lake), while Acanthamoeba will cause a slow granulomatous meningoencehalitis in immunocompromised persons (eg AIDS pt)
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Quote:
Originally Posted by heights View Post
Yeah, it's c. acanthamoeba.

Acanthamoeba infect the cornea (in immunocompetent persons) when contact lenses are not properly cleaned. This corneal infection (keratitis) can lead to blindness.

Also, remember that Naegleria fowleri will cause a sudden deadly meningoencephalitis in immunocompetent persons (think of the kids on spring break who went diving in a warm water lake), while Acanthamoeba will cause a slow granulomatous meningoencehalitis in immunocompromised persons (eg AIDS pt)
excellent, and through which anatomic structure does Naelgleria pass?? tic tac tic tac
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Bravooo everyone:

the answer is Acanthamoeba indeed

Risk factor: extended wearing of contact lenses , inadequate disinfection, wearing lenses while swimming

complications: if untreated cataract, increase intraocular pressure, loss of vision

Diagnosis: slit lamp examination: thickened epithelium and rough corneal nerves, and corneal ring

biopsy: irregular polygonal cyst

Treatment: topical miconazole and neomycine,
surgery at the corneal ring stage
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Quote:
Originally Posted by tinhi View Post
excellent, and through which anatomic structure does Naelgleria pass?? tic tac tic tac
cribriform plate
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Quote:
Originally Posted by Mondoshawan View Post
cribriform plate
correct, Bravo
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