Testing by Sysmex UF-100 flow cytometer and with bacterial culture in a diagnostic laboratory: a comparison.
A large proportion of the samples tested in routine diagnostic microbiology laboratory are urine samples. The gold standard is bacterial culture, but a high proportion of samples cultured are negative. Unnecessary testing can be reduced and an improved service provided by an effective screening test. The Sysmex UF-100 flow cytometer has been developed to count cells and casts accurately in urine samples. Its performance in a screening test was compared with bacterial culture by using 1005 consecutive urine samples, and cut-off criteria were established. Cut-off values of 3000 bacteria/microl and 111 WBC/microl provided the best discrimination. Of 1005 samples, 606 (60%) would be cultured. Sixteen samples that were not selected according to these criteria were culture positive. This was considered acceptable for our routine use. The use of a testing algorithm incorporating the Sysmex UF-100 flow cytometer has improved the quality and efficiency of urine testing within the routine microbiology laboratory.
Evans
R
R
Microbiology Department, Raigmore Hospital, Inverness IV2 3UJ, UK. roger.evans@haht.scot.nhs.uk
Davidson
M M
MM
Sim
L R W
LR
Hay
A J
AJ
D001424:Bacterial Infections / Q000175:diagnosis*; D001431:Bacteriological Techniques / Q000379:methods; D015169:Colony Count, Microbial; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D007958:Leukocyte Count; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D016482:Urinalysis / Q000379:methods; D014552:Urinary Tract Infections / Q000175:diagnosis*