Medical College of Wisconsin
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Evaluation of the WASPLab software to Automatically Read CHROMID CPS Elite Agar for Reporting of Urine Cultures. J Clin Microbiol 2019 Nov 06



Pubmed ID





Urine cultures are among the most common specimens received by clinical laboratories and generate a major share of the laboratory workload. Chromogenic agar can expedite culture results, but technologist review is still needed. In this study, we evaluated WASPLab™ software to interpret urine specimens plated onto CHROMID® CPS® Elite (CPSE) agar. Urine specimens submitted for bacterial culture were plated onto CPSE agar with a 1μl loop using the WASP™. Each plate was imaged after 0 and 18h of incubation and colonies were enumerated by color using the WASPLab™ software and a technologist reading from an HD monitor. Results were reported as negative if <10 colonies/plate were detected. LIS time stamps were used to measure time to result. A total of 1,581 urine cultures were tested. Sensitivity and specificity of the software was 99.8% and 68.5%, respectively, which included 2 Manual Positive/Automation Negative (MP/AN) and 170 Manual Negative/Automation Positive (MN/AP) results. Of the 170 MN/AP specimens, 116 were caused by microcolonies missed by the technologist. The remaining MN/AP were cause by either count differences near the 10-colony threshold (n=43) or count differences >50 CFU (n=11). Use of both CPSE agar and WASPLab software improved time to result for urine culture reducing the average time to result by 4h42m for negative specimens and 3h28m for positive specimens compared to standard of care testing. These data demonstrate that use of CPSE agar and automated plate reading has the potential to improve turnaround time while maintaining high sensitivity and reducing urine culture workload.

Author List

Faron ML, Buchan BW, Samra H, Ledeboer NA


Matthew L. Faron PhD Assistant Professor in the Pathology department at Medical College of Wisconsin

jenkins-FCD Prod-398 336d56a365602aa89dcc112f077233607d6a5abc