Sunday, 2 December 2007


Name: Khong Fay Seah
Age: 27 yrs old
Sex: Female

Complaints: Fever, chills, dysuria (painful urination)
Diagnosis: UTI
Specimen: Urine

Test ordered (Main Lab): Urine FEME (microscopy, dipstick)


Step 1:
A drop of uncentrifuged urine placed into a KOVA chamber, and examined with restricted light intensity under the high-dry objective of an ordinary clinical microscope can reveal leukocytes, epithelial cells, and bacteria.

Finding 105 organisms per millililiter can conclude UTI.
Normal hematocrit/HB
Elevated WBC (>18,000/uL)
Innumerable white blood cells
A few RBC
Numerous bacteria

Positive Urine dipstick nitirite suggest strongly bacteria growth in the urine tract.

Step 3:
A gram-stained smear of uncentrifuged urine that shows gram-negative rods is diagnostic of UTI

Step 4: in the micro lab

· Culture urine using a bacteriologic loop calibrated to deliver 0.01 or 0.00mL to agar plates.
· Aerobic culture ( maconkey and blood agar plates) & incubated overnight @ 37 degree.

In active pyelonephritis, the number of bacteria in urine collected by uretheral catheter is relatively lo.

While accumulating in the bladder, bacteria multiply rapidly and soon reach >105/mL (not contamination). The presence of more than 105/mL of the same type of bacteria per milliliter, establish a diagnosis of active infection. E.coli might be causing bacteria.

If the growth of different types of bacteria fewer than 104/mL, suggest that organisms come from normal flora or contaminants.

This female patient with acute dysuria and UTI will have 102/mL-103/mL.

If the cultures are negative but clinical signs of UTI are present, ureteral obstruction, tuberculosis can be considered.

E.coli cause 80-90% of acute bacterial lower tract infection in young women. The patient with acute cystitis has negative urine cultures for bacteria. Other possible causing bacteria: Staphylococcus, Neisseria Gonorrhoeae, Klebsiella, Enterobacter.

If such infection is caused by E.coli, identification and susceptibility testing of bacteria are not necessary.


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