kiranmayi
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A 24-year-old female with a past history of recurrent urinary tract infections presents to your office with suprapubic pain, fever, and urinary urgency and frequency. Urinanalysis reveals that the urine has an alkaline pH, increased leukocyte esterase, and increased nitrate. What is a likely cause of the patient's infection?
A. E. coli
B. Proteus mirabalis
C. Pseudomonas
D. Staphylococcus saphrophyticus
E. Streptococcus pneumoniae
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| peekay
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a- probably because pt has recurrent s&s
on the other side alkaline pH makes me think P.miralis.but i go with--- A
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| asmi
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Staph. saprophyticus.--->well known for UTI in adolescent females.
proteus mirabilis, pseudomonas------->known for causing UTI in catheterized pts.
E.coli------> mots common cause of UTI in females and catheterized pts.
urine positive for leukocyte esterase and nitrite----> suggest the presence of GNB's
But here in this case nitrate is not reduced to nitrite.
alkaline urine---->suggest the presence of urea splitting organisms ...proteus,pseudomonas,providentia,staphylococcus.
I would go with D as the answer...
Kiran if you could add more points to differentiate.....i would appreciate
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| mjl1717
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proteus
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| asmi
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here is a good artical..
http://www.courses.ahc.umn.edu/pharmacy/5825/uti....
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| asmi
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one more...its very good
http://www.aafp.org/afp/990301ap/1225.html
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| kiranmayi
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Answer is B. Proteus mirabalis
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| Malaysian
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I thought the nitrates would be decreased and increased nitrites instead?
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| nutmeg
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Proteus produce UREASE creating alkaline environment. The rest do not have this property.
increase urease -> hydrolysis of urea -> formation of ammonia -> increase pH of urine -> formation of struvite stones -> block urine formation -> UTI
note: Adolescent is 13 to 19 y/o... 24 y/o is considered an adult female. Nitrate should be reduced to nitrite to consider E. coli
I've seen patients w/ Pseudomonas - they looked greenish
S. pneumoniae?? I don't think so
S. saprophyticus?? maybe... since int's common among adult females, sexually active (but sexual activity wasn't mentioned in history)
But the proteus group are known to produce alakaline urine
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| nutmeg
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Proteus produce UREASE creating alkaline environment. The rest do not have this property.
increase urease -> hydrolysis of urea -> formation of ammonia -> increase pH of urine -> formation of struvite stones -> block urine formation -> UTI
note: Adolescent is 13 to 19 y/o... 24 y/o is considered an adult female. Nitrate should be reduced to nitrite to consider E. coli
I've seen patients w/ Pseudomonas - they looked greenish
S. pneumoniae?? I don't think so
S. saprophyticus?? maybe... since int's common among adult females, sexually active (but sexual activity wasn't mentioned in history)
But the proteus group are known to produce alakaline urine
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| bactitech
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I did the urine bench last night - I think I set up about a dozen E. coli sensis vs. NO Proteus sensis on the patients I had. EC is the most common urinary tract pathogen; however, I'm not sure that it can cause the alkalinity that PRMI does. Urines that have Proteus in them really STINK (like old dirty diapers or a crummy nursing home).
Staph. sapro. can be a pathogen of women of childbearing age, but we see far more EC's in this age group than St. sapro.
Pseudo is not normally a pathogen in this age group unless the patient has been chronically ill. One usually only seens Providencia in patients that have had long term indwelling catheters as in nursing homes. S. pneumoniae is only a urinary tract pathogen if it spills over from a lung, blood, or CSF infection i.e. it is not the primary source. I have seen it, but rarely.
We see LOTS of enterococci, but please be aware that this organism does not necessarily give a positive nitrate exam in the urinalysis.
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| Renegade
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You mentioned enterococci. What sort of circumstances could make us suspect of enterococci infection in a situation like this?
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| bactitech
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I'm sorry - I really don't know, as I'm not a doc :-). The two websites in this thread give a lot of good information, though, and are really worth taking a look at. If you are going into family practice or internal medicine, you will be fielding many many UTI's over the next few years, so it will behoove all of you to bone up on all this stuff. We do the work for four hospitals and outreach, and the urine culture bench is by far our busiest. We probably do 200-250 urine cultures a DAY Monday-Friday. The docs order LOTS of pee specimens :-(. Multiply what we do, our competitor hospital probably does close to that, and another private lab does half of that a day, and that's a LOT of urine cultures. We're a medium sized city (350-400,000 metro area).
You will be talking to your patients a LOT about this.
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