부산대학교 도서관

Objective: In the clinical microbiology laboratory, up to 80% of urine cultures for urinary tract infections (UTIs) are often negative. We investigated whether the use of the flow cytometry cut-off value may reduce the number of urine samples that need to be cultured when used as a quick screening method; to rule out bacteriuria using Sysmex UF-1000i. Methods: To screen for bacteria or leukocytes in 215 urine samples, flow cytometry and urine culture were used. Using a receiver operator characteristic (ROC) curve analysis, we investigated the ideal cut-off value for additional bacterial culture. Researchers were able to show the significance of selecting the best cut-off values for urine cultures, using urine samples of 7,550 patients with suspected UTIs from the emergency room of the E-Da Hospital. Results: In 215 urine samples, ROC curve analysis identified bacteria count 100 bacterial (BACT) µL or leukocyte count 10 white blood cell (WBC) µL as potential indicators of bacterial growth. When the bacterial count cut-off was 100 BACT µL, a urine sample had a negative predictive value of 91.2% and a sensitivity of 95.2%, which meant that in around 37.9% of instances, a urine sample could be reported as negative without a culture. Due to an increase in growth rate from 43.3% to 86% and a decrease in the significant culture negative rate from 43.3% to 8.9%, the adoption of cut-off predictors can prevent 2,862 samples, out of 7,550 urine samples, from being further plated. Conclusions: When urine samples are analyzed for UTIs, several culture-positive results are discovered. The effort and response time involved with culture plating are reduced by using flow cytometry to rule out urine samples quickly and effectively, without detectable bacterial growth.