Accuracy of rapid microcapillary direct antibiotic susceptibility testing for urine samples collected with bacteriostatic boric acid from patients with suspected urinary tract infection

This study evaluated a rapid microcapillary direct-from-urine (RMD) antibiotic susceptibility testing (AST) method for patients with suspected urinary tract infections (UTIs), including samples preserved with boric acid.

Key findings:

• High accuracy: RMD AST showed ~97% concordance with standard reference methods.
• Fast results: Average turnaround time was ~5.9 hours, significantly faster than conventional AST.
• Robust performance: Agreement between samples with and without boric acid was ~99%, indicating that boric acid does not interfere with the test.

Conclusion:
RMD AST is a reliable and rapid method for determining antibiotic susceptibility directly from urine samples, even when boric acid is used for preservation. This approach can support faster clinical decision-making and improved antimicrobial stewardship without requiring additional sample processing.