Rapid Identification and Susceptibility Testing Directly From Urine Specimens, Reducing Turnaround Time, a Step...

Area of Science:

• Clinical Microbiology
• Diagnostic Technology
• Infectious Diseases

Background:

• Urinary tract infections (UTIs) are common bacterial infections with lengthy diagnostic turnaround times (TAT) of 48-72 hours.
• Current diagnostics rely on culture and antimicrobial susceptibility testing (AST), delaying treatment.
• Rapid diagnostics are crucial for effective antimicrobial stewardship.

Purpose of the Study:

• To reduce diagnostic TAT for common uropathogens like *Escherichia coli* and *Klebsiella pneumoniae*.
• To implement a combined protocol of direct MALDI-TOF MS identification and direct AST.
• To improve diagnostic stewardship and enable timely patient intervention.

Main Methods:

• Direct MALDI-TOF MS was used for pathogen identification from urine specimens.
• Direct AST was performed and read at multiple time points (4, 6, 8, 16-20 hours).
• Results were compared against culture-based MALDI-TOF MS and VITEK II for accuracy and agreement.

Main Results:

• Direct MALDI-TOF MS achieved high identification accuracy (88.2% standardization, 90.7% validation).
• Direct AST demonstrated >90% categorical agreement for most antibiotics by 6-8 hours.
• The combined protocol reduced TAT by 39-43 hours.

Conclusions:

• A combined protocol of direct MALDI-TOF MS and direct AST is feasible for rapid UTI diagnosis.
• Final identification and AST results can be obtained within 6-8 hours of sample receipt.
• This approach supports diagnostic stewardship and timely therapeutic decisions.