1. Does flow cytometry have a role in preliminary differentiation between urinary tract infections sustained by gram positive and gram negative bacteria? An Italian polycentric study.
- Author
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Gessoni, Gianluca, Saccani, Graziella, Valverde, Sara, Manoni, Fabio, and Caputo, Marco
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CYTOMETRY , *URINARY organs , *GRAM-negative bacteria , *BODY fluids , *EXCRETION - Abstract
Background Urine culture is the most frequently requested test for a Microbiology Lab. A reliable screening tool would be of paramount importance both to clinicians and laboratorians, provided that it could get fast and accurate negative results in order to rule-out urinary tract infection (UTI). Materials and methods We evaluated 1907 consecutive urine samples from outpatients. Culture was performed on chromogenic agar with 1 μL loop, using 10 5 CFU/mL as a limit of positive growth. Using Sysmex Uf-1000i analyzer we evaluated bacteria forward scatter (B_FSC) and fluorescent light scatter (B_FLH) in a preliminary discrimination step for UTI caused by Gram + or Gram − bacteria. Results We got 512 positive samples. A mono-microbial infection was observed in 490 samples; two bacterial strains were isolated in 22 samples, so 534 bacterial strains were found: 392 Gram−, 133 Gram + and 9 yeasts. Comparing Gram + and Gram − bacteria we observed a statistically significant difference for B_FSC but not for B_FLH. In this application experimental cut-off value for B_FSC was 25ch. Using this cut-off to perform a presumptive identification of UTI sustained by Gram-+ bacteria, we observed a SE 0.68, SP 0.84. Conclusion Our data although preliminary suggest that B_FSC could be useful in presumptive exclusion of UTI caused by Gram-positive bacteria. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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