[khanar]

A 65 years old chronic alcoholic presented with fever and night sweats since 2 weeks that did not improve on pencillin and cephalosporin therapy. History revealed prior episodes of severe drowsiness, night sweats, and foul smelling expectoration.
Which of the following is likely the cause of these symptoms?
a- Klebsialla pneumoniae
b- Streptococcus pneumoniae
c- Bacteroids
d- Staphylococcus aureus
e- Legionella pneumophila

 

[khanar]

Hmmm
I think this guy is having Klebsiella

 

[HouseWannabe]

i think it's E. Legionella produces B-lactamases which would explain why penicillin wouldn't have worked, and Cephalosporin wouldn't work on this subclass of bacteria. It's also one of the differential bacteria for alcoholics.

 

[DrSeddik]

I choose D

 

[khanar]

I say bacteroids

 

[khanar]

The correct answer is C

This alcoholic had impaired consciousness (severe drowsiness) which precipitated aspiration pneumonia (most commonly caused by commensal anaerobes such as bacteroids) which then progressed into lung abscess that is notoriously difficult to treat with conventional antibiotics and may even sometimes necessitates surgical resection.

 

[DrSeddik]

This alcoholic had impaired consciousness (severe drowsiness) which precipitated aspiration pneumonia (most commonly caused by commensal anaerobes such as bacteroids) which then progressed into lung abscess that is notoriously difficult to treat with conventional antibiotics and may even sometimes necessitates surgical resection.

I was between this one and Staph., I thought the alcoholic thing is a distractor, and the past episodes of night sweating and expectoration were bronchiectasis and he is having a staph. infection now which is also resistant to antibiotics.

 

[rasheed]

Aspiration localisation

A related useful thread is found here
http://www.usmle-forums.com/usmle-step-1-bits-pieces/1793-aspiration-localisation.html#post5879