CONTRIBUTI SCIENTIFICI – Scientific Papers
Biochimica Clinica 2012; 36(2) 107-111
Comparison of Sysmex UF-100 and UF-1000i with urine culture for the diagnosis of urinary tract infections
1Servizio di Medicina di Laboratorio, Ospedale di Monselice, PD
2Servizio di Medicina di Laboratorio, Ospedale Civile di Chioggia, VE
Urinary tract infections (UTI) are a common clinical condition. The gold standard for diagnosis is still the bacterial culture, even though a large proportion of evaluated samples are negative. Unnecessary cultures can be reduced by an effective screening test. The aim of this study was to compare two cytometers for rapid diagnosis of UTI. Using 209 urine samples submitted to our laboratory for microbiological examination, we evaluated the analytical performance of the new urine cytometer UF-1000i in comparison with the previous generation analyzer UF-100 (both from Sysmex). We compared bacteria (BACT) and leukocyte (WBC) counts performed by UF-1000i and UF-100 with colony-forming units (CFU) quantification on citrate lactose electrolytes deficient (CLED) agar to assess the best cutoff values. Moreover, a correlation between BACT and WBC quantification performed by the two instruments was carried out. In comparison with 1×108 CFU/L, cut-off values of 1.25×108 BACT/L and 4×107 WBC/L by using UF-1000i, and 3×109 BACT/L and 3.5×107 WBC/L by using UF-100 were obtained, respectively. While WBC quantification by UF-1000i and UF-100 showed a strong correlation (r=0.98), BACT quantification displayed a poor correlation (r=0.59).