A-266 Comparative Evaluation of Bacteriostatic Efficacy in Preserved Room-Temperature vs. Unpreserved Refrigerated Urine Containers

Background Urinary tract infections (UTIs) are common bacterial infections, diagnosed through urine culture, which typically requires refrigerated storage to prevent bacterial overgrowth. Alternatively, collection and preservative devices such as the novel UriSponge (Copan Diagnostics, Murrieta, California) are used to maintain specimen integrity. This study evaluates the bacteriostatic efficacy of the newly reformulated UriSponge in preserving urine samples at room-temperature and during delayed processing conditions. No studies currently exist that demonstrate its effectiveness in a clinical setting. Methods Midstream urine samples were collected and aliquoted at a clinic, then transported to the testing laboratory to facilitate assessment of refrigerated and UriSponge-preserved conditions. Aliquots were stored refrigerated (unpreserved) and at room temperature (UriSponge-preserved) until plating. Samples were plated on Brilliance UTI Clarity agar (ThermoFisher Scientific, Waltham, MA) at ∼11 and ∼34 hours post-collection. A total of 451 specimens were assessed using WASPLab and PhenoMATRIX. Cultures were reviewed for agreement across different sample storage conditions. Results UriSponge-stored aliquots demonstrated strong agreement with unpreserved urine aliquots. Categorical interpretations of no growth (NG), non-significant growth (NSG), significant growth (SG), and mixed growth (MG) were assigned. Categories of NG, NSG, and MG were considered clinically insignificant while SG was considered clinically significant. Aliquots plated ∼11 hours post-collection demonstrated 95% clinical categorical agreement. Aliquots plated ∼34 hours post-collection demonstrated 90% clinical categorical agreement. A 2% and 4% increase in organism recovery was observed in 34-hour non-preserved and preserved cultures, respectively, compared to 11 hours, with Enterococcus sp. being the most frequently recovered organism in both conditions. Loss of significant organisms occurred in 2% and 4% of non-preserved and preserved cultures, respectively, with Lactobacillus sp. showing the most decreased recovery in extended storage, regardless of preservative use. Conclusion The reformulated UriSponge device demonstrated strong bacteriostatic effectiveness in preserving urine samples collected at the clinic site and stored at room temperature, with high clinical categorical agreement when compared to refrigerated, unpreserved samples. The findings suggest that UriSponge is a reliable option for collecting and maintaining sample integrity, ensuring accurate uropathogen recovery in cases where delays in specimen processing occur.