Total Laboratory Automation Versus Manual Processing in Urine Culture Inoculation and Interpretation: A Hospital...

Background/Objectives: Urine culture processing is labor-intensive and prone to operator-dependent variability. This study compared total laboratory automation (TLA; BD Kiestra™) with manual urine culture processing in terms of workflow efficiency, diagnostic performance, and operator variability. Methods: Three hundred midstream urine specimens were processed using manual and automated workflows, stratified by technologist experience (expert ≥10 years; non-expert <2 years) and shift. Metrics included setup time, cleanup time, and total staff time (TST). Colony-forming unit (CFU) recovery using 1 µL manual inoculation, 10 µL manual inoculation, and 10 µL TLA inoculation of 20 known positive specimens was compared. Diagnostic performance was assessed against the 1 µL manual reference using serially diluted specimens at a ≥10⁵ CFU/mL threshold. Results: TLA reduced the setup time from 10 min 10 s to 2 min 05 s for experts and from 13 min 37 s to 2 min 20 s for non-experts (79-83% reduction). TST decreased from 11 min 06 s to 2 min 30 s and from 14 min 37 s to 3 min 15 s, respectively (77-78% reduction). Cleanup time showed smaller reductions that did not reach statistical significance in the paired analysis. Manual processing showed greater operator-dependent variability, which TLA substantially reduced. CFU recovery was concordant in high-burden specimens, with method-dependent differences in routine diagnostic samples. Conclusions: TLA improves urine culture workflow efficiency, reduces operator-dependent variability, and shows concordant semi-quantitative performance compared to the standard manual reference within the limits of a proof-of-concept design, supporting its implementation to enhance consistency and throughput in clinical microbiology laboratories.