Elevated UTI Biomarkers in Symptomatic Patients with Urine Microbial Densities of 10,000 CFU/mL Indicate a Lower Threshold for Diagnosing UTIs

The literature lacks consensus on the minimum microbial density required for diagnosing urinary tract infections (UTIs). This study categorized densities of urine specimens from symptomatic UTI patients aged ≥ 60 years and correlated them with detected levels immune response biomarkers neutrophil gelatinase-associated lipocalin (NGAL), interleukin-8 (IL-8), interleukin-1-beta (IL-1β). objective was to identify associated significant elevation these in order determine an optimal threshold UTIs. Biobanked midstream voided samples were analyzed identification quantification using standard culture (SUC) multiplex-polymerase chain reaction (M-PCR) testing, while NGAL, IL-8, IL-1β measured via enzyme-linked immunosorbent assay (ELISA). all significantly elevated at 10,000 cells/mL when M-PCR (p < 0.0069) or equivalent colony-forming units (CFUs)/mL SUC 0.0104) compared no detectable microbes. With both PCR SUC, a two more well > CFU/mL, respectively. association between ≥10,000 cells CFU per mL suggests that this lower may be suitable than 100,000 CFU/mL