In the past
week of infectious disease classes, we discussed urinary tract infection (UTI) in
groups, and each group took responsibilities to answer and present parts of the
content in the lecure notes. Here is a case study about the UTI.
Case Study: E.
coli
A 19 year old
female, she had nausea w/out vomiting 5 days prior to admission, 1 day before
admission, she got left blank pain, fever 38.8 with chills, and she noticed an
increased urine frequency and foul smelling urine. Physician examination showed
left costovertebral angle tenderness. The results of urinalysis were: Notable
for >50 WBC/ high power field, 3-10RBC/ high power field, and 3+ bacteria; Urinary
culture SBA and Mac were all positive for >100,000 CFU of an org/ml.
Diagnosis: Pyelonephritis
(Upper UTI)
Analysis:
1. Almost all
UTI are caused by bacteria which enter the urethral and move ascending to
bladder sometimes kidneys. Most possible pathogens are E. coli, Klebsiella pneumonia,
other Enterobacteriaceae, and staphylococcus saprophyticus.
2. Pyelonephritis
(Upper UTI) is infection of kidney parenchyma, calyces, and pelvis. With
symptoms costovertebral angle percussion tenderness, chills, fevers, flank pain,
nausea, and vomiting. Most common organism causing this type of infection is E.
coli.
3. Urinary tract
infections are more frequent in women because women have a shorter urethra,
which makes it easier for bacteria to move ascending to the upper urinary tract and provide less barrier to the
bacterial invasion
. 4. To make the diagnosis of the infection
bacteria, we need to observe the bacteria colony morphology on the SBA and Mac
agar. SBA - large, gray, semi-opaque, may be beta-hemolytic; MAC – red surrounded
by a zone of precipitates bile. Gram Stain for microscopic showed large
gram-negative bacilli. Additional test spot indole result was positive. The
bacteria isolated from the urine culture could be reported as E. coli.
