English 
Italian CONTRIBUTI SCIENTIFICI – Scientific Papers
Volume:
Biochimica Clinica 2014; 38(6) 625-629
Pubblicato on-line:
DOI:
Flow citometry for screening acute urinary tract infections and differentiation between Gram positive and Gram negative bacteria
AUTORI
1Clinical Chemistry and Microbiology Laboratory, Orlandi General Hospital, Bussolengo (VR)
2Clinical Pathology Department, Madonna della Navicella Hospital, Chioggia (VE)
3Clinical Pathology Department, Civil Hospital, Monselice (PD)
ABSTRACT
Urine culture is the most frequent test in microbiology laboratories. A screening tool, providing fast and reliable results to rule-out urinary tract infection (UTI), would be of great importance. We studied 1043 consecutive urine samples by Sysmex UF-1000i analyzer. Comparison was made by robotic urine culture on chromogenic agar with 1 μL loop, using 105 CFU/mL as a limit of positive growth. We evaluated bacteria quantification for rapid exclusion of UTI and bacteria forward scatter (B_FSC) in preliminary discrimination of UTI caused by Gram positive or Gram negative bacteria. For exclusion of UTI, the best cut-off value was 130 bacteria/μL. At this threshold, the sensitivity (SE) was 0.98 and the specificity (SP) 0.75. For exclusion of UTI sustained by Gram positive bacteria, the best cut-off value for B_FSC was 25ch. At this threshold, SE was 0.68 and SP was 0.89.