Performance of the Sysmex UF1000i system in screening for significant bacteriuria before quantitative culture of aerobic/facultative fast-growth bacteria in a reference hospital.
OBJECTIVE
To evaluate the performance of the Sysmex UF1000i automatic urine screening system in the quantitative culture of fast-growth aerobic/facultative bacteria.


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 >10(5) 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 >10(5) CFU ml(-1) or of ≥10(4) 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.


CONCLUSIONS
The Sysmex UF1000i system can be adapted for bacteriuria screening by the use of an appropriate cut-off point.


CONCLUSIONS
This screening system significantly reduces the workload and produces very few false positives and negatives.
Microbiology Area, University Hospital Virgen de las Nieves, Granada, Spain. josegf@ugr.es
J
J
Gutiérrez-Fernández
A
A
Lara
M F
MF
Bautista
J
J
de Dios Luna
P
P
Polo
C
C
Miranda
J M
JM
Navarro
D000328:Adult; D019540:Area Under Curve; D001419:Bacteria / Q000254:growth & development* / Q000302:isolation & purification; D001431:Bacteriological Techniques / Q000295:instrumentation / Q000379:methods*; D001437:Bacteriuria / Q000175:diagnosis*; D002648:Child; D005260:Female; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D007958:Leukocyte Count; D011237:Predictive Value of Tests; D011247:Pregnancy; D012372:ROC Curve; D012680:Sensitivity and Specificity; D016482:Urinalysis / Q000295:instrumentation / Q000379:methods*