Clinical utility of PCR compared to conventional culture and sensitivity testing for management of complicated urinary tract infections in adults: Part II.Evaluation of diagnostic concordance, discordant results, and antimicrobial selection efficacy

Purpose: Complicated urinary tract infections (cUTIs) are difficult to manage due to their polymicrobial nature and resistance to standard therapies. In current clinical practice, the management of a cUTI often starts with broad-spectrum antimicrobials until culture and sensitivity (C&S) results are available, but these diagnostic delays further hinder treatment efficacy. Polymerase Chain Reaction (PCR) offers a faster alternative. This study evaluates PCR's utility compared to C&S, focusing on agreeability, discordant results, clinical outcomes, and antimicrobial selection efficacy to improve cUTI management. Materials and Methods: The clinical study was conducted in two parts: the primary study focused on patients with cUTIs, while the sub-study involved healthy individuals without signs or symptoms of urinary tract infection (UTI). All collected samples underwent analysis using both PCR and C&S for comparison. Building on the first part of the study, the research evaluated outcome measures related to discordant analysis. Results: Overall, our study supports good agreement between PCR and C&S in positive cases (95.32 % at baseline and 88.06 % at end of study (EOS)) but reveals some discordance in negative cases (62.91 % at baseline and 38.30 % at EOS). The negative percent agreement (NPA) in the sub-study on the healthy population was 70.16 %. Further analysis of discordant results revealed that symptomatic patients treated for PCR-positive infections trended toward better clinical outcomes (77.45 % vs. 71.42 %) and higher rates of microbiological eradication (53.92 % vs. 50 %) compared to those treated for C&S-positive infections. Additional analysis on antimicrobial use and microbiological aspects revealed that the PCR group received more oral medication-based treatments, while the C&S group received other forms (intramuscular or bladder irrigation). In cases of discordant results, there were more PCR-positive but culture-negative cases than PCR-negative but culture-positive cases. Conclusions: Our clinical utility study data suggests that PCR-guided management of cUTIs is overall superior to conventional C&S, offering several advantages. PCR has the potential to enhance patient care by enabling the early adoption of narrower antibiotic therapies, improving clinical outcomes, and ensuring the effective selection of antimicrobials. A PCR-guided management plan could be particularly beneficial in managing patients with cUTIs, addressing infections that are occasionally overlooked with current C&S-guided treatment protocols.