Performance of the Sysmex UF1000i system in screening for significant bacteriuria before quantitative culture of aerobic/facultative fast-growth bacteria in a reference hospital
Article first published online: 24 JUL 2012
© 2012 The Authors Journal of Applied Microbiology © 2012 The Society for Applied Microbiology
Journal of Applied Microbiology
Volume 113, Issue 3, pages 609–614, September 2012
How to Cite
Gutiérrez-Fernández, J., Lara, A., Bautista, M.F., de Dios Luna, J., Polo, P., Miranda, C. and Navarro, J.M. (2012), Performance of the Sysmex UF1000i system in screening for significant bacteriuria before quantitative culture of aerobic/facultative fast-growth bacteria in a reference hospital. Journal of Applied Microbiology, 113: 609–614. doi: 10.1111/j.1365-2672.2012.05369.x
- Issue published online: 14 AUG 2012
- Article first published online: 24 JUL 2012
- Accepted manuscript online: 22 JUN 2012 11:10AM EST
- Manuscript Accepted: 17 JUN 2012
- Manuscript Revised: 8 JUN 2012
- Manuscript Received: 6 APR 2012
Vol. 115, Issue 6, 1439, Article first published online: 15 NOV 2013
- urinary tract infection;
To evaluate the performance of the Sysmex UF1000i automatic urine screening system in the quantitative culture of fast-growth aerobic/facultative bacteria.
Methods and Results
A standard procedure was used to recover fast-growth aerobic/facultative micro-organisms in 1225 samples, applying (Sysmex®) flow cytometry for parallel bacteria and leucocyte counts. According to the area under the receiver operating characteristic curve, the optimal cut-off values to detect bacteriuria >105 colony forming units (CFU) ml−1 were 690/μl for bacteria and 38/μl for leucocytes (sensitivity, 92%; specificity, 65%; positive predictive value [PPV], 39%; and negative predictive value [NPV], 97%). The use of a single cut-off point of 150 bacteria μl−1 to detect significant bacteriuria of >105 CFU ml−1 or of ≥104 CFU ml−1 plus leucocyturia obtained similar results (sensitivity, 89%; specificity, 54%; PPV, 31%; and NPV, 96%) and allowed 45·7% of the samples to be rapidly excluded.
The Sysmex UF1000i system can be adapted for bacteriuria screening by the use of an appropriate cut-off point.
Significance and Impact of the Study
This screening system significantly reduces the workload and produces very few false positives and negatives.