Rapid UTI antibiotic test may deliver same-day susceptibility results

A UK study reports a direct-from-urine microcapillary test that returned antibiotic susceptibility results in about six hours and agreed with standard laboratory methods in most samples.

A team at the University of Reading and the University of Southampton reported a rapid microcapillary direct‑from‑urine antibiotic susceptibility test (RMD AST). The device uses thin tubes loaded with antibiotics that are dipped into urine and optical imaging to detect whether bacterial growth continues. In the study, susceptibility results were produced in two to ten hours, with a mean time of about 5.85 hours. The research was published in JAC‑Antimicrobial Resistance and funded by the UK's National Institute for Health and Care Research. Key findings: - The RMD AST was evaluated on 352 diagnostic remnant urine samples; results agreed with the reference culture-based method in 96.5% of samples containing a single organism (Escherichia coli or Staphylococcus aureus). - Susceptibility readouts were reported in two to ten hours, with an average of 5.85 hours. - To test for interference from boric acid (used to stabilize urine samples), researchers split 90 fresh urine samples with and without boric acid; RMD AST results agreed with the reference method in 98.8% of those paired samples and showed no indication that boric acid caused false negatives for growth detection. - The test assessed resistance to seven antibiotics commonly used as first-line treatments for UTIs and was compared against standard laboratory methods. - The authors note that additional evaluation at other hospitals with different antibiotic-resistance profiles is needed. Summary: The RMD AST produced rapid susceptibility results that largely matched standard testing in these initial hospital-based comparisons, and the presence of boric acid did not appear to interfere in the split-sample checks. Further evaluations at other hospitals with different resistance patterns are planned or recommended to determine how broadly the test performs. Undetermined at this time.