Urine should be collected first thing in the morning after overnight incubation in the bladder.
A midstream clean catch or catheterized specimen is best, as this minimizes the presence of genital flora. Do not use urine from a collection bag or bed pan. Twenty-four hour urine samples are unacceptable.
Yeasts recovered from routine urine bacteriology cultures of catheterized urine or urine obtained by sterile procedure should be identified and reported regardless of colony count. However, the isolation of yeasts from clean catch specimens must be interpreted with caution and is not significant without additional support from other clinical and laboratory investigations.
Negative bacteriological cultures from patients with clinical evidence of an infection should be sealed with tape and maintained at 26C for 4 weeks to exclude the presence of a slow growing fungus.
Urine samples must be processed as soon as possible, a delay of longer than two hours at room temperature may impede the detection of some fungi. Store at 4oC if short delays in processing are anticipated.
- Centrifuge the urine for 10-15 minutes at 2000 rpm. Decant the supernatant and pool the sediment if necessary.
- Prepare a direct smear of the sediment in KOH for direct microscopy. Note PAS, Gram or India ink preparations may also be helpful.
- Inoculate 0.05-0.1 ml of the sediment onto Sabouraud's agar with gentamicin and chloramphenicol and incubate duplicate cultures at 26C & 35C. Maintain cultures for 4 weeks.