671 - Same Day Identification of Enterobacteriaceae Directly from Urine Samples

Background: Urinary tract infections (UTIs) are one of the most common infections, associated with 10.5 million outpatient visits annually. Fast and accurate identification (ID) of bacteria causing a UTI would allow for immediate targeted therapy, as opposed to conventional methods which take one to three days.  The Accelerate Pheno^® system (ACC, Accelerate Diagnostics Inc., Tucson, AZ, USA) provides microbial ID and susceptibility (AST) from positive blood cultures.  Our objective was to determine ACC’s potential to quickly ID bacterial pathogens directly from urine.

Methods: Remnant urine samples with >100K colony forming units (CFU)/mL of gram-negative bacteria as determined by quantitative plating were obtained from the clinical lab.  1.5ml of urine was dispensed into a capsule and loaded onto the Accelerate PhenoPrep™ module. This module automatically performs wash steps to separate bacteria from human cells and other debris.  The processed sample was loaded onto ACC for analysis using a custom designed assay which detects the presence of bacteria and employs an Enterobacteriaceae family specific FISH probe.  The results were compared to standard of care ID results.

Results: There were 10 E. coli and 1 C. koseri among the eleven samples tested.  Baseline concentration of samples immediately prior to testing ranged from 2.5 x 10⁶ to 1.08 x 10¹⁰ CFU/mL (average 4.19 x 10⁹). After specimen processing, average concentration was 2.14 x 10⁹ CFU/mL and average recovery was 42.83%.  ACC detected bacteria and identified it as Enterobacteriaceae in 11/11 samples (100%).  Average sample prep time was 55 min.  Average time to Enterobacteriaceae ID was 8.6 hrs.  Average total time to ID, including specimen processing, was 9.5 hrs.Table 1: Results of Direct from Urine Testing


Conclusion: ACC identified Enterobacteriaceae directly from remnant urine specimens in an average of 9.5 hours, approximately 24 to 48 hours faster than conventional methods.  ACC was able to be adapted for use in urine samples.  Future directions include improving the assay to identify bacteria to the species level and adding AST testing.  This shows promise in providing fast actionable UTI diagnosis, allowing for tailored antibiotic therapy.
 
*This information concerns a use that has not been approved or cleared by the Food and Drug Administration.