Sysmex UF-1000i performance for screening yeasts in urine

Abstract

We tested the capacity of the Sysmex UF-1000i system to detect yeasts in urine by screening a total of 22 132 urine samples received for culture in our microbiology laboratory during 1 year. We also analyzed different dilutions of previously filtered urine inoculated with a strain of Candida albicans. With clinical samples, a single cut-off point of 50 yeast-like cells (YLCs)/μL detected candiduria ≥10 000 colony forming units (CFU)/mL and >100 000 CFU/mL with a sensitivity of 87.3%/95.4%, a specificity of 97%, a negative predictive value of 95.9%, and a positive predictive value of 9.3%/5.7%. With the simulated samples, a linear relationship was observed between the dilution factor and the number of cells detected by UF-1000i. This instrument appears to be able to reliably rule out candiduria of a magnitude of at least 10 000 CFU/mL and facilitate urine sample screening, thereby providing fast results. The Sysmex UF1000i system can be adapted for candiduria screening by the use of an appropriate YLCs/μL cut-off point that takes account of the prevalence of candiduria in the population.