Clinical Usefulness of BACT Count and BACT-Info Flag of UF-5000 for Screening for Urinary Tract Infection and Prediction of Gram-Negative Bacteria

Clin Lab. 2022 Dec 1;68(12). doi: 10.7754/Clin.Lab.2022.220217.

Abstract

Background: A rapid and reliable screening test for urinary tract infection (UTI) is needed to reduce the turn-around time and to rule out negative results of urine culture. The aim of this study was to evaluate the performance of BACT count and BACT-Info flag of the UF-5000 for screening for UTI.

Methods: A total of 1,063 urine specimens from April to September 2019 were included in this study. We evaluated the diagnostic performance of white blood cell (WBC) count, BACT count, BACT-Info flag, and UTI flag in UF-5000 by comparing with the urine culture results.

Results: Of the urine specimens, 16.7% were culture-positive (≥ 105 CFU/mL) with 15 being yeast positive. A BACT count of > 685.3/µL showed the best diagnostic performance with 93.8% sensitivity and 90.2% specificity. We confirmed that the combination of BACT count (685.3/µL) and BACT-Info flag would be appropriate to use in a clinical laboratory (sensitivity 91.5%, specificity 90.5%). Based on this combination, the sensitivity and specificity of the Gram-negative flag were 95.5% and 94.8%.

Conclusions: We recommend the use of a combination of BACT count (685.3/µL) and BACT-Info for UTI diagnosis. This combination is more appropriate for Gram-negative bacteria, and it would be useful for selecting empirical treatment.

MeSH terms

  • Flow Cytometry
  • Gram-Negative Bacteria
  • Humans
  • Leukocyte Count
  • Sensitivity and Specificity
  • Urinalysis / methods
  • Urinary Tract Infections* / microbiology