659. Evaluation of a Rapid Diagnostic Assay for Early Detection of Bacteriuria

Background Patients with suspected urinary tract infection (UTI) are often prescribed an empiric antibiotic treatment due to delays in obtaining results of urine cultures. The BacterioScan System measures the turbidity of incubating urine specimens to provide a qualitative determination of bacteriuria at a density of >5 × 104 colony-forming units (CFU)/mL within approximately 3 hours. We examined the utility of the BacterioScan assay in predicting bacteriuria and assessed the potential impact of this test to reduce the number of urine cultures processed. Methods Urine samples received for culture in the microbiology laboratory of the Cleveland VA Medical Center were collected daily between September 2018 and December 2018. For each specimen, we performed a bacterioscan diagnostic test and compared it with the result of the traditional culture and urinalysis if available. Urinary cultures were categorized into 4 groups as defined in Figure 1. We compared the sensitivity and specificity of the bacterioscan vs. urinalysis (leukocyte esterase and/or pyuria) results. Results 120 urine samples were tested. As shown in Table 1, the BacterioScan had better sensitivity and specificity than the urinalysis for detection of positive urine cultures. The use of the BacterioScan to rule out UTI could have accurately spared 69 of 120 (57.5%) samples from traditional culture and prevented 26 of 120 (21.6%) from possible misinterpretation as infection due to reporting of growth. BacterioScan resulted in 4 of 31 (12.9%) false negatives, but all occurred when positive cultures were due to viridans streptococci or uropathogens in numbers below 100,000 CFU.ml. Conclusion The BacterioScan system is a rapid diagnostic test that provides early information on urine culture results that could help to avoid overuse of empirical antimicrobials in patients with suspected UTI and decrease the workload of the Microbiology Laboratory. Disclosures All authors: No reported disclosures.